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Posted: 8/17/2014 2:48:00 PM EDT
[#1]
been a huge fan of 6.8 for many years
If you handload ( you should).... uses common .270 bullets and (before the panic ) common rifle powders 
6.8 forum... http://68forums.com/forums/index.php I really like the 110gr VMAX and SIERRA pro hunter. 
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Posted: 8/17/2014 7:25:14 PM EDT
[#2]
Both are great AR rounds & will serve you well, within 400y.
The 6.5G has more bullets with better BC *on average' than the 6.8. Thus, better down range past 400y. The 6.8 has more overall factory support, incl. ammo. It just depends on what you want & uses. Get SPC II chambered barrel or equivalent. Most barrel/rifle companies use the SPC II chamber. The common bullet range is 85-120. There are a few 130s & 140gr that will fit a 6.8 case, most notable is the 140gr Berger. The common range for deer/hogs range fro 95 to 120gr. |
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Posted: 8/18/2014 9:10:01 AM EDT
[#3]
Quote HistoryQuoted:
been a huge fan of 6.8 for many years If you handload ( you should).... uses common .270 bullets and (before the panic ) common rifle powders <a href="http://smg.photobucket.com/user/derek45/media/AR/wilson68spc_zps84d9f2ab.jpg.html" target="_blank">http://img.photobucket.com/albums/v488/derek45/AR/wilson68spc_zps84d9f2ab.jpg</a> 6.8 forum... http://68forums.com/forums/index.php I really like the 110gr VMAX and SIERRA pro hunter. http://www.hunt101.com/data/500/68bullets31m.JPG Try the 90gr TNT for plinking. Very accurate, even out to 400 yards. At 200 you can shoot well under an inch if you have a good barrel and load combo.... |
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Posted: 8/18/2014 9:33:04 AM EDT
[#4]
been a huge fan of 6.8 for many years
If you handload ( you should).... uses common .270 bullets and (before the panic ) common rifle powders if you handload step up to the 6.8's big brother and get 2970+ out of 120 gr |
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Posted: 8/18/2014 1:44:06 PM EDT
[#5]
Since every time some asks about the 6.8 the Grendel gets brought up by someone.
Why does everyone talk about BC and hunting in the same sentence when referencing an advantage the Grendel may have over the 6.8? When BC really has little bearing on how a hunting bullet performs. The real truth is a Grendel may have a minor advantage at ranges over 400 yards, but only target shooting. Either cartridge is to weak to be a hunting caliber past 400 yards. Ethically at least. As well as to hunting if the .300 ACC or 6.5 were better on hogs or deer people would be migrating that way, but they are not. They are going 6.8 Current trends with manufacturers verifies this so its not disputable. Almost if not all the comparisons I have read compare the SPC1 against the Grendel, the SPCII against the Grendel is much closer past 400 yards. As to the ammo debate, the last year has seen 6.8 target ammo with very good re-loadable brass under 15 bucks a box shipped readily available from numerous sources. I find this not true with the 6.5 or 300 ACC. As well ammo is everywhere for the 6.8 in the last 6 months, in many flavors. There is no need to reload this caliber anymore if a person does not want to. Parts availability is the same story, 6.8 is very available from many places Then there is bolt strength, feeding reliability, barrel length concerns that come in to play as well. I looked at all 3 before choosing the 6.8 in Feb 13. In current times and current development of the cartridge I feel the 6.8 has major advantages over the other 2 choices. In 2014 the 6.8 IS the way to go in a performance AR15. This in addition to my 5.56 which I also still love and shoot. I dont really care to shoot surplus ammo in it, except for training which is still the cheapest training alternative in an AR15. I load 69 and 77 gr SMK and my favorite the 70gr Barnes TSX. The 70gr Barnes TSX make a .556 a viable hunting round out to 250 yards where legal. But its spendy, any good hunting ammo in any caliber is not cheap thought now is it. This is in no way meant to bash anyone elses choices or weapons. If you like it, if it suits your needs then fire away. (not at me) lol |
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Posted: 8/18/2014 2:51:05 PM EDT
[#6]
when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery.
my first upper was an AR15performance rifle, its the one with the NF on it. while I was waiting on my build some of the other forum members gave me a heads up on a CTD sale on SSA ammo with the club discount it was like 11.35 per box for good hot ammo. Others made sure that I was all setup to reload with my Dillon 650 one guy even called me and walked me through running my first batch of ammo, (thanks Paulie) I could not have found a nicer group of guys to hang out with on a forum. No question is dumb and no one makes fun of you on that forum unless you are busted while trolling |
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Posted: 8/18/2014 3:08:14 PM EDT
[#7]
Quote HistoryQuoted:
when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery. my first upper was an AR15performance rifle, its the one with the NF on it. while I was waiting on my build some of the other forum members gave me a heads up on a CTD sale on SSA ammo with the club discount it was like 11.35 per box for good hot ammo. Others made sure that I was all setup to reload with my Dillon 650 one guy even called me and walked me through running my first batch of ammo, (thanks Paulie) I could not have found a nicer group of guys to hang out with on a forum. No question is dumb and no one makes fun of you on that forum unless you are busted while trolling + 1 |
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Posted: 8/18/2014 3:15:43 PM EDT
[#8]
I like mine a lot, especially w/ hornady 120gr sst's.
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Posted: 8/18/2014 3:29:53 PM EDT
[#9]
Why BC matters and why the "they're equal out to 400yds" statement doesn't work. Here's an example where we take the two, stack the deck in the 6.8's favor (with serious questions about safety for the breech) by using a 20" 6.8 SPCII loaded in excess of what I think is safe, but is still listed in Accurate Powder's data for the 120gr SST, a great hunting bullet from Hornady.
Then we take that same bullet type from Hornady, but for the 6.5 Grendel, shoot the factory load from a 16" barrel, and compare them. We can do the same thing with an 18" 6.8 vs. a 14.5" Grendel, a 16" 6.8 vs. a 12.5" Grendel, etc. I've been doing these comparisons for years, but the Grendel = long range advantage only myth doesn't seem to die. It's not a knock on the 6.8, but just a misconception that there are some superior hunting qualities in the cartridge over the Grendel within common distances. If you want to say that a hot-loaded 20" 6.8 SPCII has 69 more ft-lbs at 25yds than a 16" Grendel with factory Hornady load, then that would be valid, or 43 more foot-lbs at 75yds, or 31 more ft-lbs at 100yds, etc. For energy, they match up at 175yds. Grendel has less drift from the start, but they are close within common hunting distances. Trajectory of the two is within fractions of an inch out to 400yds, the 20" hot hand load 6.8 vs. the 16" Grendel with factory 123gr SST. In recent testing with strain gauge, the Hornady 123gr SST is averaging around 49,000psi chamber pressure. It's a well loved bullet by both camps for sure, and has been used to take a lot of game since it was introduced. When you look at the numbers, outsiders looking in will probably think a lot of people have gotten wrapped around the axle for nothing. 20" 6.8 SPCII loaded to excessive pressures (58,500psi) listed by Accurate Powders with the 120gr Hornady SST BC .420 
Range Velocity Energy Trajectory TOF Drift 16" 6.5 Grendel with Hornady 123gr SST factory load, recorded mv over chrono avg 2450fps, .510 BC 
Range Velocity Energy Trajectory TOF Drift Quoted:
Quoted:
when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery. my first upper was an AR15performance rifle, its the one with the NF on it. while I was waiting on my build some of the other forum members gave me a heads up on a CTD sale on SSA ammo with the club discount it was like 11.35 per box for good hot ammo. Others made sure that I was all setup to reload with my Dillon 650 one guy even called me and walked me through running my first batch of ammo, (thanks Paulie) I could not have found a nicer group of guys to hang out with on a forum. No question is dumb and no one makes fun of you on that forum unless you are busted while trolling + 1 Been on the Grendel Forum for years, including the old forum. That experience is something I've never seen with new or old members. The Grendel Forum is one of the few places you can go to avoid being mocked or pressured into some crazy price point. I got into the Grendel with a $269 barrel/bolt combo from Midway back in 2009. Mags have always been sub $20. There has always been affordable ammo, as well as standard and premium ammo. |
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Posted: 8/18/2014 4:35:37 PM EDT
[#10]
"Loaded to excessive pressures" spoken like somone who is not up to speed on what the 6.8 is doing now.
2550fps out of a 16in 6.8 (my Bison barrel not an ARP which is slightly (50fps) faster) is NOT over pressure for a SPCII chamber. Which is what I get with 27.3gr's of AA2200 and an OAL of 2.295, .6 MOA I might add.. So your statement that it takes a 20in barrel is invalid, respectfully. Actually a 20in barrel is 100fps faster now and will run 2650 fps safely with quality handloads. I have loaded them to fire 2650fps out of my barrel and that is to hot, signs of case head separation, flat primers and swipes. 2550fps out of a SPCII chamber is safe. I could run closer to 2600fps but want my brass to last. Disclaimer - always work up when loading for your barrel. Of other note, I also can ring steel all day long at 600 yards at my local range ( the longest it goes) with my hand loaded 130gr Berger VLD's (2480fps) and 140gr Berger VLD's (2420fps), with my wimpy 6.8 16in barrel. NO and I mean NO powder or bullet manufacturer is going to list loads that are "over pressure", or dangerous as you put it. The liability alone would make it very stupid for them to do so. This is one of the issues we have with the SPCII chamber is that when reloading there is no data based on the SPCII chamber its all based on the SPCI chamber. Thank Remington for that one! As to hunting performance I think both given speed and energies that are close the larger diameter projectile also lends a larger wound cavity. I will agree that in 2009 the Grendel probably was more attractive. However not in 2014. I know I'm beating a horse thats been beat over and over but lets use 2014 info shall we. Quote HistoryQuoted:
Why BC matters and why the "they're equal out to 400yds" statement doesn't work. Here's an example where we take the two, stack the deck in the 6.8's favor (with serious questions about safety for the breech) by using a 20" 6.8 SPCII loaded in excess of what I think is safe, but is still listed in Accurate Powder's data for the 120gr SST, a great hunting bullet from Hornady. Then we take that same bullet type from Hornady, but for the 6.5 Grendel, shoot the factory load from a 16" barrel, and compare them. We can do the same thing with an 18" 6.8 vs. a 14.5" Grendel, a 16" 6.8 vs. a 12.5" Grendel, etc. I've been doing these comparisons for years, but the Grendel = long range advantage only myth doesn't seem to die. It's not a knock on the 6.8, but just a misconception that there are some superior hunting qualities in the cartridge over the Grendel within common distances. If you want to say that a hot-loaded 20" 6.8 SPCII has 69 more ft-lbs at 25yds than a 16" Grendel with factory Hornady load, then that would be valid, or 43 more foot-lbs at 75yds, or 31 more ft-lbs at 100yds, etc. For energy, they match up at 175yds. Grendel has less drift from the start, but they are close within common hunting distances. Trajectory of the two is within fractions of an inch out to 400yds, the 20" hot hand load 6.8 vs. the 16" Grendel with factory 123gr SST. In recent testing with strain gauge, the Hornady 123gr SST is averaging around 49,000psi chamber pressure. It's a well loved bullet by both camps for sure, and has been used to take a lot of game since it was introduced. When you look at the numbers, outsiders looking in will probably think a lot of people have gotten wrapped around the axle for nothing. 20" 6.8 SPCII loaded to excessive pressures (58,500psi) listed by Accurate Powders with the 120gr Hornady SST BC .420 http://www.hornady.com/store/images/P/8347%206.8%20Remington%20SPC%20120gr%20SST.jpg Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2543 1723 -1.50 0.0000 0.00 25 2490 1652 0.03 0.0298 -0.06 50 2438 1584 1.20 0.0602 -0.22 75 2386 1517 2.01 0.0913 -0.51 100 2336 1453 2.44 0.1231 -0.91 125 2285 1391 2.48 0.1556 -1.43 150 2236 1332 2.09 0.1887 -2.08 175 2187 1274 1.27 0.2227 -2.86 200 2138 1218 -0.00 0.2573 -3.78 225 2090 1164 -1.75 0.2928 -4.83 250 2043 1112 -3.99 0.3291 -6.03 275 1996 1062 -6.76 0.3662 -7.38 300 1950 1014 -10.07 0.4042 -8.88 325 1905 967 -13.95 0.4431 -10.53 350 1861 922 -18.43 0.4830 -12.35 375 1817 879 -23.54 0.5238 -14.34 400 1774 838 -29.31 0.5655 -16.51 16" 6.5 Grendel with Hornady 123gr SST factory load, recorded mv over chrono avg 2450fps, .510 BC http://www.hornady.com/store/images/P/8152%206.5%20Grendel%20123gr%20SST.jpg Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2450 1639 -1.50 0.0000 0.00 25 2407 1583 0.10 0.0309 -0.05 50 2365 1528 1.32 0.0623 -0.19 75 2323 1474 2.16 0.0943 -0.44 100 2282 1422 2.59 0.1269 -0.78 125 2241 1372 2.61 0.1600 -1.23 150 2201 1323 2.19 0.1938 -1.79 175 2161 1275 1.33 0.2282 -2.46 200 2121 1229 -0.00 0.2632 -3.23 225 2082 1183 -1.81 0.2989 -4.13 250 2043 1140 -4.13 0.3353 -5.14 275 2004 1097 -6.96 0.3723 -6.28 300 1966 1056 -10.33 0.4101 -7.54 325 1929 1016 -14.27 0.4486 -8.93 350 1892 978 -18.79 0.4879 -10.46 375 1855 940 -23.92 0.5279 -12.12 400 1819 904 -29.67 0.5687 -13.91 Been on the Grendel Forum for years, including the old forum. That experience is something I've never seen with new or old members. The Grendel Forum is one of the few places you can go to avoid being mocked or pressured into some crazy price point. I got into the Grendel with a $269 barrel/bolt combo from Midway back in 2009. Mags have always been sub $20. There has always been affordable ammo, as well as standard and premium ammo. Quote HistoryQuoted:
Why BC matters and why the "they're equal out to 400yds" statement doesn't work. Here's an example where we take the two, stack the deck in the 6.8's favor (with serious questions about safety for the breech) by using a 20" 6.8 SPCII loaded in excess of what I think is safe, but is still listed in Accurate Powder's data for the 120gr SST, a great hunting bullet from Hornady. Then we take that same bullet type from Hornady, but for the 6.5 Grendel, shoot the factory load from a 16" barrel, and compare them. We can do the same thing with an 18" 6.8 vs. a 14.5" Grendel, a 16" 6.8 vs. a 12.5" Grendel, etc. I've been doing these comparisons for years, but the Grendel = long range advantage only myth doesn't seem to die. It's not a knock on the 6.8, but just a misconception that there are some superior hunting qualities in the cartridge over the Grendel within common distances. If you want to say that a hot-loaded 20" 6.8 SPCII has 69 more ft-lbs at 25yds than a 16" Grendel with factory Hornady load, then that would be valid, or 43 more foot-lbs at 75yds, or 31 more ft-lbs at 100yds, etc. For energy, they match up at 175yds. Grendel has less drift from the start, but they are close within common hunting distances. Trajectory of the two is within fractions of an inch out to 400yds, the 20" hot hand load 6.8 vs. the 16" Grendel with factory 123gr SST. In recent testing with strain gauge, the Hornady 123gr SST is averaging around 49,000psi chamber pressure. It's a well loved bullet by both camps for sure, and has been used to take a lot of game since it was introduced. When you look at the numbers, outsiders looking in will probably think a lot of people have gotten wrapped around the axle for nothing. 20" 6.8 SPCII loaded to excessive pressures (58,500psi) listed by Accurate Powders with the 120gr Hornady SST BC .420 http://www.hornady.com/store/images/P/8347%206.8%20Remington%20SPC%20120gr%20SST.jpg Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2543 1723 -1.50 0.0000 0.00 25 2490 1652 0.03 0.0298 -0.06 50 2438 1584 1.20 0.0602 -0.22 75 2386 1517 2.01 0.0913 -0.51 100 2336 1453 2.44 0.1231 -0.91 125 2285 1391 2.48 0.1556 -1.43 150 2236 1332 2.09 0.1887 -2.08 175 2187 1274 1.27 0.2227 -2.86 200 2138 1218 -0.00 0.2573 -3.78 225 2090 1164 -1.75 0.2928 -4.83 250 2043 1112 -3.99 0.3291 -6.03 275 1996 1062 -6.76 0.3662 -7.38 300 1950 1014 -10.07 0.4042 -8.88 325 1905 967 -13.95 0.4431 -10.53 350 1861 922 -18.43 0.4830 -12.35 375 1817 879 -23.54 0.5238 -14.34 400 1774 838 -29.31 0.5655 -16.51 16" 6.5 Grendel with Hornady 123gr SST factory load, recorded mv over chrono avg 2450fps, .510 BC http://www.hornady.com/store/images/P/8152%206.5%20Grendel%20123gr%20SST.jpg Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2450 1639 -1.50 0.0000 0.00 25 2407 1583 0.10 0.0309 -0.05 50 2365 1528 1.32 0.0623 -0.19 75 2323 1474 2.16 0.0943 -0.44 100 2282 1422 2.59 0.1269 -0.78 125 2241 1372 2.61 0.1600 -1.23 150 2201 1323 2.19 0.1938 -1.79 175 2161 1275 1.33 0.2282 -2.46 200 2121 1229 -0.00 0.2632 -3.23 225 2082 1183 -1.81 0.2989 -4.13 250 2043 1140 -4.13 0.3353 -5.14 275 2004 1097 -6.96 0.3723 -6.28 300 1966 1056 -10.33 0.4101 -7.54 325 1929 1016 -14.27 0.4486 -8.93 350 1892 978 -18.79 0.4879 -10.46 375 1855 940 -23.92 0.5279 -12.12 400 1819 904 -29.67 0.5687 -13.91 Quoted:
Quoted:
when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery. my first upper was an AR15performance rifle, its the one with the NF on it. while I was waiting on my build some of the other forum members gave me a heads up on a CTD sale on SSA ammo with the club discount it was like 11.35 per box for good hot ammo. Others made sure that I was all setup to reload with my Dillon 650 one guy even called me and walked me through running my first batch of ammo, (thanks Paulie) I could not have found a nicer group of guys to hang out with on a forum. No question is dumb and no one makes fun of you on that forum unless you are busted while trolling + 1 Been on the Grendel Forum for years, including the old forum. That experience is something I've never seen with new or old members. The Grendel Forum is one of the few places you can go to avoid being mocked or pressured into some crazy price point. I got into the Grendel with a $269 barrel/bolt combo from Midway back in 2009. Mags have always been sub $20. There has always been affordable ammo, as well as standard and premium ammo. |
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Posted: 8/18/2014 5:42:41 PM EDT
[#11]
Quote HistoryQuoted:
when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery. I could not have found a nicer group of guys to hang out with on a forum. Interesting. My experience has been just the opposite. A decade ago I became interested in both cartridges as potential alternatives to 5.56 NATO for military use. Wrote an article comparing the two rounds, which was published in 2005, followed by an update article a few years later. In both articles I concluded that 6.8 SPC was the better option for military use. On the 65grendel forum, there were respectful objections to portions of my analysis, but Bill Alexander himself commented that he thought I was fair, despite my conclusion. In marked contrast, the reaction on 68forums was almost unanimously very hostile towards me, even though I had opined that their pet cartridge was the better overall choice. On the 65grendel forum, diverse opinions are not only tolerated, they're usually welcomed. On 68forums, anyone who doesn't adhere to the "6.8 SPC is superior in everyway" party line, is subjected to hate-filled posts and accusations of trolling. |
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Posted: 8/18/2014 6:05:46 PM EDT
[#12]
Quote HistoryQuoted:
Interesting. My experience has been just the opposite. A decade ago I became interested in both cartridges as potential alternatives to 5.56 NATO for military use. Wrote an article comparing the two rounds, which was published in 2005, followed by an update article a few years later. In both articles I concluded that 6.8 SPC was the better option for military use. On the 65grendel forum, there were respectful objections to portions of my analysis, but Bill Alexander himself commented that he thought I was fair, despite my conclusion. In marked contrast, the reaction on 68forums was almost unanimously very hostile towards me, even though I had opined that their pet cartridge was the better overall choice. On the 65grendel forum, diverse opinions are not only tolerated, they're usually welcomed. On 68forums, anyone who doesn't adhere to the "6.8 SPC is superior in everyway" party line, is subjected to hate-filled posts and accusations of trolling. Quote HistoryQuoted:
Quoted:
when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery. I could not have found a nicer group of guys to hang out with on a forum. Interesting. My experience has been just the opposite. A decade ago I became interested in both cartridges as potential alternatives to 5.56 NATO for military use. Wrote an article comparing the two rounds, which was published in 2005, followed by an update article a few years later. In both articles I concluded that 6.8 SPC was the better option for military use. On the 65grendel forum, there were respectful objections to portions of my analysis, but Bill Alexander himself commented that he thought I was fair, despite my conclusion. In marked contrast, the reaction on 68forums was almost unanimously very hostile towards me, even though I had opined that their pet cartridge was the better overall choice. On the 65grendel forum, diverse opinions are not only tolerated, they're usually welcomed. On 68forums, anyone who doesn't adhere to the "6.8 SPC is superior in everyway" party line, is subjected to hate-filled posts and accusations of trolling. 2005 might as well be 1905 as far as the 6.8 development history is considered. Not sure what kind of hostility you received, but a lot of people still trot out old data using Remington's fucked up chamber. |
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Posted: 8/18/2014 6:10:03 PM EDT
[#13]
In marked contrast, the reaction on 68forums was almost unanimously very hostile towards me, even though I had opined that their pet cartridge was the better overall choice. I could see that but a lot of people still trot out old data using Remington's fucked up chamber. and in doing so they turn people away , gendel fanboys are their on worst enemy , I own neither by the way |
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Posted: 8/18/2014 6:34:52 PM EDT
[#14]
I've followed your posts for years, and appreciate the work you've done with the 6.5 Grendel, but this post is incredibly inaccurate and causes me to lose a lot of respect for you.
I've gone to the Accurate Arms load information - they do NOT distinguish between the SPCI and SPCII chambers in their load data. Which means it defaults to SPCI data because loads that are safe in an SPCII chamber are dangerously hot in an SPCI chamber, as you should know.  Quote HistoryQuoted: Why BC matters and why the "they're equal out to 400yds" statement doesn't work. Here's an example where we take the two, stack the deck in the 6.8's favor (with serious questions about safety for the breech) by using a 20" 6.8 SPCII loaded in excess of what I think is safe, but is still listed in Accurate Powder's data for the 120gr SST, a great hunting bullet from Hornady. Then we take that same bullet type from Hornady, but for the 6.5 Grendel, shoot the factory load from a 16" barrel, and compare them. We can do the same thing with an 18" 6.8 vs. a 14.5" Grendel, a 16" 6.8 vs. a 12.5" Grendel, etc. I've been doing these comparisons for years, but the Grendel = long range advantage only myth doesn't seem to die. It's not a knock on the 6.8, but just a misconception that there are some superior hunting qualities in the cartridge over the Grendel within common distances. If you want to say that a hot-loaded 20" 6.8 SPCII has 69 more ft-lbs at 25yds than a 16" Grendel with factory Hornady load, then that would be valid, or 43 more foot-lbs at 75yds, or 31 more ft-lbs at 100yds, etc. For energy, they match up at 175yds. Grendel has less drift from the start, but they are close within common hunting distances. Trajectory of the two is within fractions of an inch out to 400yds, the 20" hot hand load 6.8 vs. the 16" Grendel with factory 123gr SST. In recent testing with strain gauge, the Hornady 123gr SST is averaging around 49,000psi chamber pressure. It's a well loved bullet by both camps for sure, and has been used to take a lot of game since it was introduced. When you look at the numbers, outsiders looking in will probably think a lot of people have gotten wrapped around the axle for nothing. 20" 6.8 SPCII loaded to excessive pressures (58,500psi) listed by Accurate Powders with the 120gr Hornady SST BC .420 http://www.hornady.com/store/images/P/8347%206.8%20Remington%20SPC%20120gr%20SST.jpg Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2543 1723 -1.50 0.0000 0.00 25 2490 1652 0.03 0.0298 -0.06 50 2438 1584 1.20 0.0602 -0.22 75 2386 1517 2.01 0.0913 -0.51 100 2336 1453 2.44 0.1231 -0.91 125 2285 1391 2.48 0.1556 -1.43 150 2236 1332 2.09 0.1887 -2.08 175 2187 1274 1.27 0.2227 -2.86 200 2138 1218 -0.00 0.2573 -3.78 225 2090 1164 -1.75 0.2928 -4.83 250 2043 1112 -3.99 0.3291 -6.03 275 1996 1062 -6.76 0.3662 -7.38 300 1950 1014 -10.07 0.4042 -8.88 325 1905 967 -13.95 0.4431 -10.53 350 1861 922 -18.43 0.4830 -12.35 375 1817 879 -23.54 0.5238 -14.34 400 1774 838 -29.31 0.5655 -16.51 16" 6.5 Grendel with Hornady 123gr SST factory load, recorded mv over chrono avg 2450fps, .510 BC http://www.hornady.com/store/images/P/8152%206.5%20Grendel%20123gr%20SST.jpg Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2450 1639 -1.50 0.0000 0.00 25 2407 1583 0.10 0.0309 -0.05 50 2365 1528 1.32 0.0623 -0.19 75 2323 1474 2.16 0.0943 -0.44 100 2282 1422 2.59 0.1269 -0.78 125 2241 1372 2.61 0.1600 -1.23 150 2201 1323 2.19 0.1938 -1.79 175 2161 1275 1.33 0.2282 -2.46 200 2121 1229 -0.00 0.2632 -3.23 225 2082 1183 -1.81 0.2989 -4.13 250 2043 1140 -4.13 0.3353 -5.14 275 2004 1097 -6.96 0.3723 -6.28 300 1966 1056 -10.33 0.4101 -7.54 325 1929 1016 -14.27 0.4486 -8.93 350 1892 978 -18.79 0.4879 -10.46 375 1855 940 -23.92 0.5279 -12.12 400 1819 904 -29.67 0.5687 -13.91 Been on the Grendel Forum for years, including the old forum. That experience is something I've never seen with new or old members. The Grendel Forum is one of the few places you can go to avoid being mocked or pressured into some crazy price point. I got into the Grendel with a $269 barrel/bolt combo from Midway back in 2009. Mags have always been sub $20. There has always been affordable ammo, as well as standard and premium ammo. Quote HistoryQuoted: Why BC matters and why the "they're equal out to 400yds" statement doesn't work. Here's an example where we take the two, stack the deck in the 6.8's favor (with serious questions about safety for the breech) by using a 20" 6.8 SPCII loaded in excess of what I think is safe, but is still listed in Accurate Powder's data for the 120gr SST, a great hunting bullet from Hornady. Then we take that same bullet type from Hornady, but for the 6.5 Grendel, shoot the factory load from a 16" barrel, and compare them. We can do the same thing with an 18" 6.8 vs. a 14.5" Grendel, a 16" 6.8 vs. a 12.5" Grendel, etc. I've been doing these comparisons for years, but the Grendel = long range advantage only myth doesn't seem to die. It's not a knock on the 6.8, but just a misconception that there are some superior hunting qualities in the cartridge over the Grendel within common distances. If you want to say that a hot-loaded 20" 6.8 SPCII has 69 more ft-lbs at 25yds than a 16" Grendel with factory Hornady load, then that would be valid, or 43 more foot-lbs at 75yds, or 31 more ft-lbs at 100yds, etc. For energy, they match up at 175yds. Grendel has less drift from the start, but they are close within common hunting distances. Trajectory of the two is within fractions of an inch out to 400yds, the 20" hot hand load 6.8 vs. the 16" Grendel with factory 123gr SST. In recent testing with strain gauge, the Hornady 123gr SST is averaging around 49,000psi chamber pressure. It's a well loved bullet by both camps for sure, and has been used to take a lot of game since it was introduced. When you look at the numbers, outsiders looking in will probably think a lot of people have gotten wrapped around the axle for nothing. 20" 6.8 SPCII loaded to excessive pressures (58,500psi) listed by Accurate Powders with the 120gr Hornady SST BC .420 http://www.hornady.com/store/images/P/8347%206.8%20Remington%20SPC%20120gr%20SST.jpg Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2543 1723 -1.50 0.0000 0.00 25 2490 1652 0.03 0.0298 -0.06 50 2438 1584 1.20 0.0602 -0.22 75 2386 1517 2.01 0.0913 -0.51 100 2336 1453 2.44 0.1231 -0.91 125 2285 1391 2.48 0.1556 -1.43 150 2236 1332 2.09 0.1887 -2.08 175 2187 1274 1.27 0.2227 -2.86 200 2138 1218 -0.00 0.2573 -3.78 225 2090 1164 -1.75 0.2928 -4.83 250 2043 1112 -3.99 0.3291 -6.03 275 1996 1062 -6.76 0.3662 -7.38 300 1950 1014 -10.07 0.4042 -8.88 325 1905 967 -13.95 0.4431 -10.53 350 1861 922 -18.43 0.4830 -12.35 375 1817 879 -23.54 0.5238 -14.34 400 1774 838 -29.31 0.5655 -16.51 16" 6.5 Grendel with Hornady 123gr SST factory load, recorded mv over chrono avg 2450fps, .510 BC http://www.hornady.com/store/images/P/8152%206.5%20Grendel%20123gr%20SST.jpg Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2450 1639 -1.50 0.0000 0.00 25 2407 1583 0.10 0.0309 -0.05 50 2365 1528 1.32 0.0623 -0.19 75 2323 1474 2.16 0.0943 -0.44 100 2282 1422 2.59 0.1269 -0.78 125 2241 1372 2.61 0.1600 -1.23 150 2201 1323 2.19 0.1938 -1.79 175 2161 1275 1.33 0.2282 -2.46 200 2121 1229 -0.00 0.2632 -3.23 225 2082 1183 -1.81 0.2989 -4.13 250 2043 1140 -4.13 0.3353 -5.14 275 2004 1097 -6.96 0.3723 -6.28 300 1966 1056 -10.33 0.4101 -7.54 325 1929 1016 -14.27 0.4486 -8.93 350 1892 978 -18.79 0.4879 -10.46 375 1855 940 -23.92 0.5279 -12.12 400 1819 904 -29.67 0.5687 -13.91 Quoted: Quoted: when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery. my first upper was an AR15performance rifle, its the one with the NF on it. while I was waiting on my build some of the other forum members gave me a heads up on a CTD sale on SSA ammo with the club discount it was like 11.35 per box for good hot ammo. Others made sure that I was all setup to reload with my Dillon 650 one guy even called me and walked me through running my first batch of ammo, (thanks Paulie) I could not have found a nicer group of guys to hang out with on a forum. No question is dumb and no one makes fun of you on that forum unless you are busted while trolling + 1 Been on the Grendel Forum for years, including the old forum. That experience is something I've never seen with new or old members. The Grendel Forum is one of the few places you can go to avoid being mocked or pressured into some crazy price point. I got into the Grendel with a $269 barrel/bolt combo from Midway back in 2009. Mags have always been sub $20. There has always been affordable ammo, as well as standard and premium ammo. |
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Posted: 8/18/2014 6:55:15 PM EDT
[#15]
Strange that even with those "super high dangerous" pressures from Accurate powders the 6.8 doesn't break bolt or blow up barrels. I sure wouldn't want to try to get the same velocities out of the Grendel.
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Posted: 8/18/2014 9:06:40 PM EDT
[#16]
Quote HistoryQuoted:
I could see that and in doing so they turn people away , gendel fanboys are their on worst enemy , I own neither by the way Quote HistoryQuoted:
In marked contrast, the reaction on 68forums was almost unanimously very hostile towards me, even though I had opined that their pet cartridge was the better overall choice. I could see that but a lot of people still trot out old data using Remington's fucked up chamber. and in doing so they turn people away , gendel fanboys are their on worst enemy , I own neither by the way I own both, and shoot both (and 6x45, .25/223, and .458). I actually like 6x45 a lot too as there are a ton of bullet types and weights that work well with standard 5.56 brass. They all have the good and bad points. None of them have a clear (and by clear, I mean a concise and overwhelming) advantage over the other. |
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Posted: 8/18/2014 9:07:51 PM EDT
[#17]
Quote HistoryQuoted:
Strange that even with those "super high dangerous" pressures from Accurate powders the 6.8 doesn't break bolt or blow up barrels. I sure wouldn't want to try to get the same velocities out of the Grendel. You would be shredding parts in short order, unfortunately...but I've not loaded up anything that hot in auto guns. |
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Posted: 8/18/2014 9:29:46 PM EDT
[#18]
Looking at the data above, spec II which is standard now, especially with the 1/11 twist and hybrid / poly grooves, our start loads are only a grain under max, sometimes half a grain. For instance, my start load on the 110gr Hornady was 27.5gr, and I did a ladder test up to 29.5. None of them showed signs of pressure, but the accuracy node for my barrel was between 28.5gr and 29.2. I settled at 28.5, which is 2700fps from my 16" AR P barrel , measured by two different chronographs.
My load with the 115gr and AA2200 is 28.5gr at 2530fps, but I went as high as 29.3gr at 2595fps. With that I had minor swipes on two of the ten in that load, but it was less than you get shooting 5.56NATO, just a shiny smudge. Still, the accuracy node was down at 28.5. Again, this is a 16" barrel, not the 20" you're showing. I don't use the 1680 for 90grTNTs, but Re-7, at 29.8gr at 2925fps. These loads in the spec II, 1/11 twist have been tested with a trace pressure testing system to be the same pressure as the SAAMI ammo is in a SAAMI chamber, running around 52k-55k. There are hotter loads that will run up to 58k, but most of us settle where I'm at. Now, numbers I've seen posted from several ARP 20" barrels add another 80-100fps to the numbers I get. Funny thing is, for all of this "overpressure" ammo, with guys shooting thousands and thousands of rounds, you will not hear of anyone breaking a bolt. Some shoot competition, some do classes, some own hog hunting ranches, some are full auto, and some, just shoot a hell of a lot. The only 6.8 bolts I ever heard of breaking was a bad heat treated lot early on that was traced to one lot from one company. One final thing. When all this crap was blowing up before, Harrison at ARP put out a challenge to settle it once and for all. Anybody, bring any 6.5G load, hand load, max, factory load, whatever, and he would beat it with an equal length barrel, up close, in the middle, and out at 1000. So far, nobody has taken the trip to Tennessee. |
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Posted: 8/18/2014 10:21:56 PM EDT
[#19]
I listed Accurate Powder's data because it specifically lists SPCII. There is no way of telling what chamber they used for the testing other than asking them.
The problem is that we don't see anybody in the 6.8 industry describing any testing with a standard. There are things all over the place with regard to chamber dimensions, what reamer is being used, what mags are ok for this company's rifle, versus that one's. Then the people who are credited with fixing things have actually added even more variation to the chamber, deviating from the original Murray chamber design. The whole thing was false advertised from the start by people representing themselves and embellishing who was backing it, citing Special Forces, which combined with the desire for something new in the AR15, led to the industry marketing that the 6.8 received. "This is going to be the next cartridge for Special Forces, so it's a pretty big deal. Once Special Forces adopts it, big Army will get on board, and it will be huge." This went around the floor of SHOT year after year, only to find out that the cartridge is largely the creation of one of the AMU gunsmiths, without official soliciting or support from any command within the US military, a fact that eventually led to serious consequences for that individual. Here we are, over a decade later, and still no standard. No due diligence from the industry in actually vetting the cartridge to establish a specific set of data for it, and major flaws in the way it was handled still plague it, which is then washed over by people who bought into it. The problem is, these are valid concerns that should have been ironed out by a team of professionals, but never was. PTG and the reamers that were sent to Remington for SAAMI approval, then this SPC II aren't helping either. He's trying to do the same thing to the Grendel, since he hates cutting that compound angle and being held to a standard. The fact that Remington and other big name companies never caught the SAAMI reamer screw up is another indicator that this problem is systemic, 6.8 just illustrated it in a huge way because someone finally stepped outside of the box and tried to do something different. Anybody sectioning breeches after significant round counts? What's the actual MAP? I came to the figure of 53,000psi MAP based on hoop stress calculations, which is where most ammunition manufacturers like to stay below. If any of you recall, SSA used to make a "Combat" load. They also have a "Tactical" load, and then their standard loads. Why 3 different loadings for one cartridge meant to be fired from the same gun? It makes no sense. I know the Hornady 120gr SST load is listed at 2450fps from a 16" barrel, and is probably meant to be safe in SAAMI chambers. Why hasn't there been a recall effort to eliminate the SAAMI chamber screw up, and go with one standard? The whole things reeks of amateur hour, even when looking at what happened with the big name companies. Did they buy the sales pitch that this thing had been fully vetted by the military and just go with it, in the face of safety questions being asked by their engineers? I know Remington has engineers. Regardless, the cartridge still remains unvetted, untested to a degree that it deserves, and nobody seems to be making that any better. |
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Posted: 8/18/2014 10:29:42 PM EDT
[#20]
Quote HistoryQuoted:
Strange that even with those "super high dangerous" pressures from Accurate powders the 6.8 doesn't break bolt or blow up barrels. I sure wouldn't want to try to get the same velocities out of the Grendel. I easily exceeded those velocities with my 16" Grendel using the 123gr A-MAX and CFE, but I won't be mass-producing the loads that are over 2550fps until I see some ironed-out strain gauge data. So far, Hornady's 123gr SST is averaging around 49,000psi and does 2450fps for me. Guys have used it to kill Caribou at 275yds and 400yds in Alaska, so the only ones who will really benefit from it going faster are those looking to ring steel. 6.8 SPC run at 58,500psi exceeds Grendel bolt thrust, but does have a slightly stronger bolt. I doubt there are a lot of guys pushing it to 58,000+psi in volume. If I owned one, I would stay 53,000psi or below, with the medium slow powders like you mentioned for the 120gr pills. Not a bad cartridge, but someone needs to get a handle on this thing and back it with solid engineering. A correct set of SAAMI prints would be a start. |
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Posted: 8/18/2014 10:42:31 PM EDT
[#21]
Quote HistoryQuoted:
2005 might as well be 1905 as far as the 6.8 development history is considered. Quote HistoryQuoted:
Quoted:
Quoted:
when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery. I could not have found a nicer group of guys to hang out with on a forum. Interesting. My experience has been just the opposite. A decade ago I became interested in both cartridges as potential alternatives to 5.56 NATO for military use. Wrote an article comparing the two rounds, which was published in 2005, followed by an update article a few years later. In both articles I concluded that 6.8 SPC was the better option for military use. On the 65grendel forum, there were respectful objections to portions of my analysis, but Bill Alexander himself commented that he thought I was fair, despite my conclusion. In marked contrast, the reaction on 68forums was almost unanimously very hostile towards me, even though I had opined that their pet cartridge was the better overall choice. On the 65grendel forum, diverse opinions are not only tolerated, they're usually welcomed. On 68forums, anyone who doesn't adhere to the "6.8 SPC is superior in everyway" party line, is subjected to hate-filled posts and accusations of trolling. 2005 might as well be 1905 as far as the 6.8 development history is considered. Now, that's one of the dumbest statements I've ever heard. The 6.8 SPC was in existence in 2005, but not in 1905. But, if what you're trying to say is that 6.8SPC development has advanced considerably since 2005, that's a different matter. However, my 2005 article should be judged on the state of the art as it was in 2005, not what it is in 2014. |
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Posted: 8/18/2014 10:44:00 PM EDT
[#22]
Quoted: i've been thinking about getting a different upper for my AR. For what ever reason 6.8 is what I was thinking. I've read a lot of other post that people say 6.5 Grendel would be a better choice due to down range performance. I really could not see myself shooting past 3 to 400 yards. I guess I would be more interested in the cartridge that feeds and functions the best between the two. So I guess what I'm really asking is for those who have a 6.8 why did they choose it? Thanks I went with 6.8mm SPC for a number of reasons. I wanted a caliber between 5.56 and 7.62 that had better terminal ballistics than the 5.56. I wanted a caliber that allowed me some diversity with factory ammunition - lots of choices. Lighter weight rifle than the AR10 platform was also important. The 6.8mm SPC filled the bill. Here is a pic of my LWRC M6A1 http://i40.photobucket.com/albums/e233/NikH3/LWRCM6A1_zps61c52ece.jpg Since I took this photo, I updated the trigger to a Geissele SSA-E and changed the stock to a Magpul UBR. I also created a little brother for it using the 2nd upper so now I have a 6.8mm SPC pistol http://i40.photobucket.com/albums/e233/NikH3/LWRCPistol01_zpsfef9aa2a.jpg Try it...you will like it |
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Posted: 8/18/2014 11:16:10 PM EDT
[#23]
Quote HistoryQuoted:
"Loaded to excessive pressures" spoken like somone who is not up to speed on what the 6.8 is doing now. 2550fps out of a 16in 6.8 is NOT over pressure for a SPCII chamber. 2550fps out of a SPCII chamber is safe. As to hunting performance I think both given speed and energies that are close the larger diameter projectile also lends a larger wound cavity. I will agree that in 2009 the Grendel probably was more attractive. However not in 2014. I know I'm beating a horse thats been beat over and over but lets use 2014 info shall we. Okay. If I understood your post correctly, SPCII muzzle velocity from a 16" barrel will be 2550 fps, essentially the same as what LRRPF52 posted for a 20" barrel. So, for 16" barrels, with 120gr 6.8 SST vs 123gr 6.5 SST, the 6.8 has a very slight edge in retained energy out to 175 yds, and 6.5 has a slight edge in downrange energy from 175 to 400 yds. Note also that trajectories and wind drifts are virtually identical. Does anybody seriously think that the small differences in retained energy at 0-400 yards is going to have any noticeable effect on game, let alone enable one to definitively claim either cartridge is truly superior for hunting? As for the idea that "the larger diameter projectile also lends a larger wound cavity," I would note that for most hunting, the difference in bullet diameter as loaded is quite meaningless. It is the expanded diameter that matters. Now, I have read only a small percentage of the hunting stories on 68forums and the 65grendel forum, but I get the impression that both rounds perform about the same on critters. Which seems to be confirmed by the comparable results in the following bare gel test of 110gr 6.8 TSX and 120gr 6.5 TSX: https://www.youtube.com/watch?v=BROdbEm5wqA |
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Posted: 8/18/2014 11:27:24 PM EDT
[#24]
There hasn't been any 6.8 bolls break but there has been plenty of Grendel bolts broke so which is safer? I don't recall seeing any Grendel barrels sectioned or any test shown to prove how they are tested either. If AA uses a 6R rifling profile in the ER shaw barrels they sell are their other barrels that use something different safe? Better not trust it if those barrels weren't tested. Different twist rate different rifling, it may not be safe especially in those low yield strength stainless barrels. 4150 barrels have twice the yield strength as some stainless barrels. I would never buy another stainless AR barrel unless it was a 5.56 because of the hoop strength you speak of.. How many 6.5 or Grendel chambers are their now? The original Grendel, The Grendel, The 6.5CSS, The Grendel II. The 264LBC, the 6.5 Sporter, The 6.5 BPC? Which ones work with a .125 recess bolt and which ones work with a .135 recess bolt? I would hate to get those mixed up, might be a kaboom. The same companies offering barrels with 2 different chambers, The Grendel and the Grendel II? Which one uses which bolt? Then there are barrels labeled with a Grendel chamber but throat is closer to the case because they are minimum spec and then some .137" further from the case because they are maximum Grendel Spec. Having to set the bullets to different overall lengths and not being able to use other peoples data can be troublesome. This stuff can be kind of confusing can't it? I'm glad the cartridges that are SAAMI approved don't have that problem.
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Posted: 8/18/2014 11:28:17 PM EDT
[#25]
Yes. A 120gr 6.8 SST vs. a 123gr 6.5mm SST, when entering game at the same/similar impact velocity, will behave about the same. Within 175yds, the animal won't know the difference, and I there isn't a huge difference beyond 175yds either.
The bullet enters, expands per its design parameters, and continues to create a supersonic wound channel through the tissue, then exits usually. There are guys who have hunted with both of them, even from 14" barreled Contenders, and didn't notice any difference on the animals, especially with Barnes TTSX's. The Grendel just does it with less chamber pressure, and more aerodynamic bullets. The case is very efficient with the 30 degree shoulder, and does more than what it appears to be at a glance. The 6.8 generally uses faster powders and higher pressures to move less aerodynamic pills, although there has been some work to get 120gr-140gr pills to perform with medium-slow powders like a Grendel. |
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Posted: 8/18/2014 11:52:19 PM EDT
[#26]
Quote HistoryQuoted:
Okay. If I understood your post correctly, SPCII muzzle velocity from a 16" barrel will be 2550 fps, essentially the same as what LRRPF52 posted for a 20" barrel. So, for 16" barrels, with 120gr 6.8 SST vs 123gr 6.5 SST, the 6.8 has a very slight edge in retained energy out to 175 yds, and 6.5 has a slight edge in downrange energy from 175 to 400 yds. Note also that trajectories and wind drifts are virtually identical. Does anybody seriously think that the small differences in retained energy at 0-400 yards is going to have any noticeable effect on game, let alone enable one to definitively claim either cartridge is truly superior for hunting? As for the idea that "the larger diameter projectile also lends a larger wound cavity," I would note that for most hunting, the difference in bullet diameter as loaded is quite meaningless. It is the expanded diameter that matters. Now, I have read only a small percentage of the hunting stories on 68forums and the 65grendel forum, but I get the impression that both rounds perform about the same on critters. Which seems to be confirmed by the comparable results in the following bare gel test of 110gr 6.8 TSX and 120gr 6.5 TSX: https://www.youtube.com/watch?v=BROdbEm5wqA Quote HistoryQuoted:
Quoted:
"Loaded to excessive pressures" spoken like somone who is not up to speed on what the 6.8 is doing now. 2550fps out of a 16in 6.8 is NOT over pressure for a SPCII chamber. 2550fps out of a SPCII chamber is safe. As to hunting performance I think both given speed and energies that are close the larger diameter projectile also lends a larger wound cavity. I will agree that in 2009 the Grendel probably was more attractive. However not in 2014. I know I'm beating a horse thats been beat over and over but lets use 2014 info shall we. Okay. If I understood your post correctly, SPCII muzzle velocity from a 16" barrel will be 2550 fps, essentially the same as what LRRPF52 posted for a 20" barrel. So, for 16" barrels, with 120gr 6.8 SST vs 123gr 6.5 SST, the 6.8 has a very slight edge in retained energy out to 175 yds, and 6.5 has a slight edge in downrange energy from 175 to 400 yds. Note also that trajectories and wind drifts are virtually identical. Does anybody seriously think that the small differences in retained energy at 0-400 yards is going to have any noticeable effect on game, let alone enable one to definitively claim either cartridge is truly superior for hunting? As for the idea that "the larger diameter projectile also lends a larger wound cavity," I would note that for most hunting, the difference in bullet diameter as loaded is quite meaningless. It is the expanded diameter that matters. Now, I have read only a small percentage of the hunting stories on 68forums and the 65grendel forum, but I get the impression that both rounds perform about the same on critters. Which seems to be confirmed by the comparable results in the following bare gel test of 110gr 6.8 TSX and 120gr 6.5 TSX: https://www.youtube.com/watch?v=BROdbEm5wqA Now your getting it, both cartridges are close to each other comparing 6.5 Grendel to 6.8 SPCII. The 6.8 works better with shorter barrels or even suppressed, giving more choices down the line as needs or wants change. More availability of 6.8 parts and ammo. More companies and countries on board with 6.8, heard about Jordan and Saudi Arabia? LWRC/ATK/Magpul contracts? Cheaper plinking ammo with re-loadable brass that can be sold if you dont reload to further reduce costs. (try that with Wolf ammo). Your right, static bullet diameter dosent matter in hunting. The larger the static diameter at a like speed and energy with similar bullet construction, the larger bullet will expand to a larger diameter. Larger wound cavity. Hence the reason so many people are using the 6.8 on deer and hogs. Its growing all the time, in the last year and a half especially. Due to the work of AR Performance, LWRC, Wilson Combat, Wild River Ranch, ATK, Federal, Barnes, Nosler just to name some that come to mind. Barnes, Nosler, Speer and Hornady all are building multiple 6.8 specific bullets now. Its not find .277 bullets that work anymore. Then lets talk about newer or re-introduced powders, 1200R, AA2200 both really stepped up the game with the 6.8 and reloaders. 10x, H335, H322, RE7, AA2230, Varget, TAC, AR Comp, Alliant Varmint, AA1620, AA5744 and on and on all can be used in the 6.8 Is Grendel not going thru chamber reamer issues currently. I have read that it is. The 6.8 SPCII chamber has been adopted by militaries as well as departments at home and abroad. The 90gr GOLD Dot ammo produced is seeing 100's of thousand of rounds being fired. It is over sammi 6.8 pressures. Read 32,000 rifles contracted and an undisclosed amount of "training" ammo. If you going to state ideas in 2014, get all the current facts first. I have watched and studied this debated for a year and a half now. All I see is 6 to 10 year old drivel. Stanc I think you fought the 6.8 cartridge so much in the early days that the guys at 6.8 Forums just dont want to hear it anymore. Me I dont mind ya but I'm a new guy on the 6.8 block. |
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Posted: 8/19/2014 12:08:43 AM EDT
[#27]
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Now, that's one of the dumbest statements I've ever heard. The 6.8 SPC was in existence in 2005, but not in 1905. But, if what you're trying to say is that 6.8SPC development has advanced considerably since 2005, that's a different matter. However, my 2005 article should be judged on the state of the art as it was in 2005, not what it is in 2014. Quote HistoryQuoted:
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when I was looking for a better hunting AR15 I checked out both forums and I asked about cost. On the grendel forum I was mocked and told if I had to ask I can't afford to own one, then I asked the same question on the 6.8 forums and I got a fair and accurate information with no GD asshatery. I could not have found a nicer group of guys to hang out with on a forum. Interesting. My experience has been just the opposite. A decade ago I became interested in both cartridges as potential alternatives to 5.56 NATO for military use. Wrote an article comparing the two rounds, which was published in 2005, followed by an update article a few years later. In both articles I concluded that 6.8 SPC was the better option for military use. On the 65grendel forum, there were respectful objections to portions of my analysis, but Bill Alexander himself commented that he thought I was fair, despite my conclusion. In marked contrast, the reaction on 68forums was almost unanimously very hostile towards me, even though I had opined that their pet cartridge was the better overall choice. On the 65grendel forum, diverse opinions are not only tolerated, they're usually welcomed. On 68forums, anyone who doesn't adhere to the "6.8 SPC is superior in everyway" party line, is subjected to hate-filled posts and accusations of trolling. 2005 might as well be 1905 as far as the 6.8 development history is considered. Now, that's one of the dumbest statements I've ever heard. The 6.8 SPC was in existence in 2005, but not in 1905. But, if what you're trying to say is that 6.8SPC development has advanced considerably since 2005, that's a different matter. However, my 2005 article should be judged on the state of the art as it was in 2005, not what it is in 2014. Hyperbole to illustrate a point. There was so much development after 2005 that it made the development up to 2005 seem like ancient times. |
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Posted: 8/19/2014 12:08:43 AM EDT
[#28]
You know I guess I'm a 6.8 fanboi, I admit it.
Really I'm a black gun fanboi. If I could I would have many different calibers, I can afford it, but I have many interests and one is keeping the wife who does not share my passion for guns. The very best thing the OP can do is read, read , read. Go the the Grendel forum, go to 6.8 forums. Then form your own opinion. I picked the 6.8 obviously, and I'm happy with it. Which ever you pick you have my sincere wishes you find happiness with it as well. |
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Posted: 8/19/2014 12:19:26 AM EDT
[#29]
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Me I dont mind ya but I'm a new guy on the 6.8 block. Yes, yes you are. We understand you like 6.8, but all of your data has been hashed out here for years and years. The 6.8 does better from short barrels?...false The 6.8 does better suppressed? Any data to support that? More companies and Arab nations who buy every "new greatest ever gadget from the West" onboard? Welcome to marketing and Middle East arms procurement, a colossal abortion if you ever saw one. "Is best? Is best? I buy 30,000 right now!" Cheaper plinking ammo? Grendel brass will return your money at a much better rate than 6.8 brass. The same guy who made the abortion 6.8 SAAMI reamer is sending out Grendel reamers with dimensions all over the place, surprise surprise (He also claims credit for the SPC II reamer design). Not just these calibers, but .308 and anything else they touch. Welcome to the "me" generation and tooling in the firearms industry. I had to listen to several competitive shooters complain about his .308 reamers earlier this year, "It had so much freebore in the throat, it would make Roy Weatherby envious." I would have owned a few 6.8's if the Grendel had not come around. Probably would have sold them once the .224 Barnes 70gr TSX became more known. |
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Posted: 8/19/2014 1:26:15 AM EDT
[#30]
You can take it personal I dont care. Thats one of the reasons I dont spend much time here.
I am sorry I do see so many short barreled Grendels and Grendel pistols. Now that the Barnes 70 TSX is around will we be seeing your Grendel on the EE? It does not matter who was buying the 6.8 you would find issue with it. Your cheap Grendel plinking ammo is steel cased, I guess you can scrap it. Quote HistoryQuoted:
Yes, yes you are. We understand you like 6.8, but all of your data has been hashed out here for years and years. The 6.8 does better from short barrels?...false The 6.8 does better suppressed? Any data to support that? More companies and Arab nations who buy every "new greatest ever gadget from the West" onboard? Welcome to marketing and Middle East arms procurement, a colossal abortion if you ever saw one. "Is best? Is best? I buy 30,000 right now!" Cheaper plinking ammo? Grendel brass will return your money at a much better rate than 6.8 brass. The same guy who made the abortion 6.8 SAAMI reamer is sending out Grendel reamers with dimensions all over the place, surprise surprise (He also claims credit for the SPC II reamer design). Not just these calibers, but .308 and anything else they touch. Welcome to the "me" generation and tooling in the firearms industry. I had to listen to several competitive shooters complain about his .308 reamers earlier this year, "It had so much freebore in the throat, it would make Roy Weatherby envious." I would have owned a few 6.8's if the Grendel had not come around. Probably would have sold them once the .224 Barnes 70gr TSX became more known. Quote HistoryQuoted:
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Me I dont mind ya but I'm a new guy on the 6.8 block. Yes, yes you are. We understand you like 6.8, but all of your data has been hashed out here for years and years. The 6.8 does better from short barrels?...false The 6.8 does better suppressed? Any data to support that? More companies and Arab nations who buy every "new greatest ever gadget from the West" onboard? Welcome to marketing and Middle East arms procurement, a colossal abortion if you ever saw one. "Is best? Is best? I buy 30,000 right now!" Cheaper plinking ammo? Grendel brass will return your money at a much better rate than 6.8 brass. The same guy who made the abortion 6.8 SAAMI reamer is sending out Grendel reamers with dimensions all over the place, surprise surprise (He also claims credit for the SPC II reamer design). Not just these calibers, but .308 and anything else they touch. Welcome to the "me" generation and tooling in the firearms industry. I had to listen to several competitive shooters complain about his .308 reamers earlier this year, "It had so much freebore in the throat, it would make Roy Weatherby envious." I would have owned a few 6.8's if the Grendel had not come around. Probably would have sold them once the .224 Barnes 70gr TSX became more known. |
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Posted: 8/19/2014 2:45:12 AM EDT
[#31]
LRRP52 spreads more disinformation about the 6.8 than anyone I have ever seen.... If there is a 6.8 thread you will find him there stirring up the 6.5 vs 6.8 mess... Why? Because he has a financial interest I'm sure.... I find it comical at this point... Scouring the Web for 6.8 threads so he can push his pet cartridge.... Get a life... Seriously.
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Posted: 8/19/2014 3:45:44 AM EDT
[#32]
Quote HistoryQuoted:
The 6.8 works better with shorter barrels or even suppressed... Quote HistoryQuoted:
The 6.8 works better with shorter barrels or even suppressed... 6.8 fans keep repeating this claim. How does 6.8 work any better in SBRs - or suppressed - than 6.5??? I know a couple of guys who shoot Grendel SBRs, with and without suppressors, and they report the weapons work just fine. ...heard about Jordan and Saudi Arabia? LWRC/ATK/Magpul contracts? Sure, I've heard. But those contracts are only for the elite Royal Guards of the two countries, not the entire armed forces. That's certainly nice, and I understand why 6.8 fans like to tout it, but the fact remains there is no army, anywhere, which has switched to 6.8 SPC. Cheaper plinking ammo with re-loadable brass that can be sold if you dont reload to further reduce costs. (try that with Wolf ammo). Well, I not only detest picking up fired cases, I'm no longer physically able to. As a result, I'd rather shoot the Wolf steel-case 6.5 ammo, than brass-case 6.8 stuff, regardless of the difference in quality or the market for once-fired brass. Your right, static bullet diameter dosent matter in hunting.
The larger the static diameter at a like speed and energy with similar bullet construction, the larger bullet will expand to a larger diameter. Larger wound cavity. Theoretically, perhaps, but if the difference in diameter is a mere 0.013", is the difference in wound cavity sizes even going to be noticeable? Is Grendel not going thru chamber reamer issues currently.
I have read that it is. I dunno. Chamber reamers is not a subject that has ever been of interest to me. |
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Posted: 8/19/2014 4:50:09 AM EDT
[#33]
Quote HistoryQuoted:
Stanc I think you fought the 6.8 cartridge so much in the early days that the guys at 6.8 Forums just dont want to hear it anymore. Hmm. I don't recall having fought the 6.8 cartridge. As I noted previously, in my 2005 Special Weapons article, I even said at that time it was a better choice for military use. What I have fought is BS, such as 6.8 fans' irrational claims that 6.5 Grendel doesn't work in short barrels, or that it can't be belt-fed. The guys on 68forums just really dislike having their anti-Grendel myths challenged. This typically results in 6.8 fans calling me a 6.5 "fanboi". It is not really true that I'm a 6.5 fan. What I actually am is a high-BC fan. I like the long, streamlined bullets used in 6.5 Grendel, but I also prefer the SPC case design. In fact, a concept cartridge I proposed several years before either 6.8 SPC or 6.5 Grendel even entered development, incorporated a high-BC 6mm bullet in a necked down .30 Remington case (parent case of 6.8 SPC). 
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Posted: 8/19/2014 9:01:44 AM EDT
[#34]
Can I get in the middle of the 6.8 vs. 6.5 pissing match? I have two M4forgery un-fired uppers, one RRA and one PSA premium that do not have a lower yet.
How do I get in to the 6.8? Will my lowers work? Mags for 5.56 work with 6.8? Can I just buy a Gen II (is that the 6.8II ?) 6.8 barrel and put it in my upper? Do I need a new bolt? I really want to get in to the 6.8 game, but my funds are limited. So what is the most budget friendly way to get in the 6.8 game? |
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Posted: 8/19/2014 9:35:06 AM EDT
[#35]
Quote HistoryQuoted:
Can I get in the middle of the 6.8 vs. 6.5 pissing match? I have two M4forgery un-fired uppers, one RRA and one PSA premium that do not have a lower yet. How do I get in to the 6.8? Will my lowers work? Mags for 5.56 work with 6.8? Can I just buy a Gen II (is that the 6.8II ?) 6.8 barrel and put it in my upper? Do I need a new bolt? I really want to get in to the 6.8 game, but my funds are limited. So what is the most budget friendly way to get in the 6.8 game? Sure you can, the Grendel boys make it easy, lol. Any lower will work. Any new barrel you buy should be SPCII and will fit right in your upper. Mid gas is best. Yes you will need a 6.8 specfic bolt as well as mags.. $200 for an ARP or Bison barrel http://bisonarmory.com/68SPC-Barrels/ Bolt http://www.midwayusa.com/product/303086/dpms-bolt-assembly-ar-15-matte?cm_vc=ProductFinding Mags http://www.ammosc.com/6-8-spc/ Muzzle device of your choice in 5/8x24 So barrel, bolt, mags, muzzle device and your in business $300 bucks or so and you can be ready for ammo Provided you switch the parts yourself. Or watch PSA and get a whole upper when on sale. ARP, Bison, Wilson Combat, PSA to name a few make good barrels. Stay away from Yankee Hill, their barrel threads are not standard 5/8x24 Oh and if your switching from rifle or carbine gas you will need a new gas tube as well. |
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Posted: 8/19/2014 10:43:44 AM EDT
[#36]
Quote HistoryQuoted:
Hmm. I don't recall having fought the 6.8 cartridge. As I noted previously, in my 2005 Special Weapons article, I even said at that time it was a better choice for military use. What I have fought is BS, such as 6.8 fans' irrational claims that 6.5 Grendel doesn't work in short barrels, or that it can't be belt-fed. The guys on 68forums just really dislike having their anti-Grendel myths challenged. This typically results in 6.8 fans calling me a 6.5 "fanboi". It is not really true that I'm a 6.5 fan. What I actually am is a high-BC fan. I like the long, streamlined bullets used in 6.5 Grendel, but I also prefer the SPC case design. In fact, a concept cartridge I proposed several years before either 6.8 SPC or 6.5 Grendel even entered development, incorporated a high-BC 6mm bullet in a necked down .30 Remington case (parent case of 6.8 SPC). http://www.g2mil.com/Jul_31_001.jpg Quote HistoryQuoted:
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Stanc I think you fought the 6.8 cartridge so much in the early days that the guys at 6.8 Forums just dont want to hear it anymore. Hmm. I don't recall having fought the 6.8 cartridge. As I noted previously, in my 2005 Special Weapons article, I even said at that time it was a better choice for military use. What I have fought is BS, such as 6.8 fans' irrational claims that 6.5 Grendel doesn't work in short barrels, or that it can't be belt-fed. The guys on 68forums just really dislike having their anti-Grendel myths challenged. This typically results in 6.8 fans calling me a 6.5 "fanboi". It is not really true that I'm a 6.5 fan. What I actually am is a high-BC fan. I like the long, streamlined bullets used in 6.5 Grendel, but I also prefer the SPC case design. In fact, a concept cartridge I proposed several years before either 6.8 SPC or 6.5 Grendel even entered development, incorporated a high-BC 6mm bullet in a necked down .30 Remington case (parent case of 6.8 SPC). http://www.g2mil.com/Jul_31_001.jpg Same people spouting the same crap, or it's new fan-bois reading shit that is ages old and already proven false. I own both, shoot both... Pick the one you like best. I bought so much brass and bullets (when they were available) that it doesn't matter to me. For me personally, the 6.8 is cheaper to run. When I bought all my supplies in bulk, it had way more availability. Seems the 6.5 is finally even in that regard now. It's about freaking time! |
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Posted: 8/19/2014 11:14:24 AM EDT
[#37]
Would an upper like this be okay
PSA Or would I be better off just changing barrel and gas tube/block? Which mags are you 6.8 guys running and why are the PRI mags higher? Thanks |
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Posted: 8/19/2014 11:23:52 AM EDT
[#38]
Quote HistoryQuoted:
6.8 fans keep repeating this claim. How does 6.8 work any better in SBRs - or suppressed - than 6.5??? I know a couple of guys who shoot Grendel SBRs, with and without suppressors, and they report the weapons work just fine. Quote HistoryQuoted:
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The 6.8 works better with shorter barrels or even suppressed... 6.8 fans keep repeating this claim. How does 6.8 work any better in SBRs - or suppressed - than 6.5??? I know a couple of guys who shoot Grendel SBRs, with and without suppressors, and they report the weapons work just fine. "Works better" doesn't mean other cartridges don't work in short barrels. The 6.8 is a very efficient case design, especially in short barrels, and develops ~80% of the velocity potential of a given load in the first 8-10" of barrel. If you look at the velocity tables you can see the extra velocity from a barrel longer than ~12 " is 50-100 fps per inch, and that is fairly consistent across all loads. Again, that's not to the exclusion of other cartridges. But I don't know how the Grendel or Blackout may compare in that area. |
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Posted: 8/19/2014 11:26:48 AM EDT
[#39]
Quote HistoryQuoted:
Can I get in the middle of the 6.8 vs. 6.5 pissing match? I have two M4forgery un-fired uppers, one RRA and one PSA premium that do not have a lower yet. How do I get in to the 6.8? Will my lowers work? Mags for 5.56 work with 6.8? Can I just buy a Gen II (is that the 6.8II ?) 6.8 barrel and put it in my upper? Do I need a new bolt? I really want to get in to the 6.8 game, but my funds are limited. So what is the most budget friendly way to get in the 6.8 game? Bolt, Barrel, mags are 6.8 specific - everything else is standard AR-15/5.56. And ammo, of course. |
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Posted: 8/19/2014 11:37:53 AM EDT
[#40]
PRI are the best mags for 6.8, they are built well and function perfectly.
New ASC mags are a close second followed by CPD |
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Posted: 8/19/2014 11:38:29 AM EDT
[#41]
< You're no comedian in a Tech Forum - F >
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Posted: 8/19/2014 9:28:12 PM EDT
[#42]
Quote HistoryQuoted:
"Works better" doesn't mean other cartridges don't work in short barrels. The 6.8 is a very efficient case design, especially in short barrels, and develops ~80% of the velocity potential of a given load in the first 8-10" of barrel. Quote HistoryQuoted:
Quoted:
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The 6.8 works better with shorter barrels or even suppressed... 6.8 fans keep repeating this claim. How does 6.8 work any better in SBRs - or suppressed - than 6.5??? I know a couple of guys who shoot Grendel SBRs, with and without suppressors, and they report the weapons work just fine. "Works better" doesn't mean other cartridges don't work in short barrels. The 6.8 is a very efficient case design, especially in short barrels, and develops ~80% of the velocity potential of a given load in the first 8-10" of barrel. Ah, okay. That, I get. It'd be nice if 6.8 fans would come up with a phrase which more accurately describes that. "Works better" has the same meaning as "functions better," which just ain't so. As best I can tell, 6.8 SBRs work no better than other calibers. |
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Posted: 8/19/2014 10:30:21 PM EDT
[#43]
Don't trust any ballistic comparisons posted here, do your own research. The people posting them are fanboys of another cartridge.
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Posted: 8/19/2014 11:10:35 PM EDT
[#44]
Quote HistoryQuoted:
Ah, okay. That, I get. It'd be nice if 6.8 fans would come up with a phrase which more accurately describes that. "Works better" has the same meaning as "functions better," which just ain't so. As best I can tell, 6.8 SBRs work no better than other calibers. "Works" in that context is speaking to terminal performance based on velocity potential in a short barrel. You can push an 85 grain bullet 2900 fps out of a 12" barrel. That's about the same as a 77 grain mk262 round out of an 18" 5.56 barrel. |
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Posted: 8/20/2014 1:03:31 AM EDT
[#45]
Quoted:
i've been thinking about getting a different upper for my AR. For what ever reason 6.8 is what I was thinking. I've read a lot of other post that people say 6.5 Grendel would be a better choice due to down range performance. I really could not see myself shooting past 3 to 400 yards. I guess I would be more interested in the cartridge that feeds and functions the best between the two. So I guess what I'm really asking is for those who have a 6.8 why did they choose it? Thanks I have a 6.8 rifle. Picked up a LWRC Six8 myself and have been loving it. The reason I chose it was actually because I enjoyed the round design and the performance out of the SPC II chamber. I did look into the Grendel but I don't really have a reloading station setup, so the 6.8 was an easier choice for me to make, as it seemed easier for me to find it both locally and online. Another factor, for me at least, was I enjoyed actually getting a PMAG for my round. I know, I know, they aren't a needed thing but I enjoy the design, durability and weight savings of having a quality polymer magazine. This is massively a me thing but it helped influence my decision. As to everyone else, this really is looking like a "My dad can beat your dad up" argument. |
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Posted: 8/20/2014 12:00:54 PM EDT
[#46]
Quote HistoryQuoted:
"Works" in that context is speaking to terminal performance based on velocity potential in a short barrel. You can push an 85 grain bullet 2900 fps out of a 12" barrel. Quote HistoryQuoted:
Quoted:
Ah, okay. That, I get. It'd be nice if 6.8 fans would come up with a phrase which more accurately describes that. "Works better" has the same meaning as "functions better," which just ain't so. As best I can tell, 6.8 SBRs work no better than other calibers. "Works" in that context is speaking to terminal performance based on velocity potential in a short barrel. You can push an 85 grain bullet 2900 fps out of a 12" barrel. I think everybody understands that, for the same barrel length and bullet weight, 6.8 SPC produces higher muzzle velocity than 6.5 Grendel. That's due to the greater chamber pressure of the cartridge, and larger "piston area" of the fatter bullet. However, unless you're having a gunfight in a phone booth, muzzle velocity isn't what should be considered in regard to terminal performance. Impact velocity is what matters, and the inferior aerodynamics of most 6.8 bullets causes the initial velocity advantage to quickly disappear downrange. So, even in that context, I'm not sure that "works better" is an accurate phrase. In any case, it's at least misleading for anyone who doesn't know what 6.8 fans mean. |
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Posted: 8/20/2014 12:12:23 PM EDT
[#47]
Quote HistoryQuoted:
I think everybody understands that, for the same barrel length and bullet weight, 6.8 SPC produces higher muzzle velocity than 6.5 Grendel. That's due to the greater chamber pressure of the cartridge, and larger "piston area" of the fatter bullet. However, unless you're having a gunfight in a phone booth, muzzle velocity isn't what should be considered in regard to terminal performance. Impact velocity is what matters, and the inferior aerodynamics of most 6.8 bullets causes the initial velocity advantage to quickly disappear downrange. So, even in that context, I'm not sure that "works better" is an accurate phrase. In any case, it's at least misleading for anyone who doesn't know what 6.8 fans mean. Quote HistoryQuoted:
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Ah, okay. That, I get. It'd be nice if 6.8 fans would come up with a phrase which more accurately describes that. "Works better" has the same meaning as "functions better," which just ain't so. As best I can tell, 6.8 SBRs work no better than other calibers. "Works" in that context is speaking to terminal performance based on velocity potential in a short barrel. You can push an 85 grain bullet 2900 fps out of a 12" barrel. I think everybody understands that, for the same barrel length and bullet weight, 6.8 SPC produces higher muzzle velocity than 6.5 Grendel. That's due to the greater chamber pressure of the cartridge, and larger "piston area" of the fatter bullet. However, unless you're having a gunfight in a phone booth, muzzle velocity isn't what should be considered in regard to terminal performance. Impact velocity is what matters, and the inferior aerodynamics of most 6.8 bullets causes the initial velocity advantage to quickly disappear downrange. So, even in that context, I'm not sure that "works better" is an accurate phrase. In any case, it's at least misleading for anyone who doesn't know what 6.8 fans mean. I don't know enough about the particulars of the Grendel to make any comparisons, unless I see the old 6.8 data pop up in the discussion. I generally compare the 6.8 to the 5.56. With the 6.8, the slight loss of velocity from a shorter barrel is not as drastic as in the 5.56. So you get real rifle performance from a sub gun sized package. I wouldn't try to or expect to shoot a 12" rifle out to 800 yards. 
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Posted: 8/20/2014 1:24:07 PM EDT
[#48]
Quote HistoryQuoted:
"Works" in that context is speaking to terminal performance based on velocity potential in a short barrel. You can push an 85 grain bullet 2900 fps out of a 12" barrel. That's about the same as a 77 grain mk262 round out of an 18" 5.56 barrel. Quote HistoryQuoted:
Quoted:
Ah, okay. That, I get. It'd be nice if 6.8 fans would come up with a phrase which more accurately describes that. "Works better" has the same meaning as "functions better," which just ain't so. As best I can tell, 6.8 SBRs work no better than other calibers. "Works" in that context is speaking to terminal performance based on velocity potential in a short barrel. You can push an 85 grain bullet 2900 fps out of a 12" barrel. That's about the same as a 77 grain mk262 round out of an 18" 5.56 barrel. Accurate Powder lists 3020fps for the Barnes 85gr at 54,997psi from a 20" barrel. Let's say that's a bad SAAMI chamber and the short throat and other abortions created with that reamer are the cause for the numbers. Are you telling me that 8" less barrel length, but a SPC II chamber design is going to make up for those 8" of barrel, so that a 12" pipe can hit 2900fps no problem? What chamber pressure are we talking about in the SPCII that allows you to push an 85gr at 2900fps from a 12" barrel? I just ran the numbers through Shooter's Notes Velocity Estimator, and when I changed the barrel length from 20" to 12", it kicked out 2759fps average, with "Velocity will be between 2709 and 2808 feet per second about 65% of the time." I used 6.8 case length of 1.676" H2O volume 34.8gr 85gr bullet weight 20" barrel length AA2200 for the powder 3020fps for listed mv from Accurate Powders 31.1gr charge weight from Accurate For the new velocity estimation, I only changed the barrel length. If AA's data was using the SAAMI chamber, and the SPCII reamer creates chambers that doesn't spike the pressure like a SAAMI chamber does, then 2900fps for a 12" isn't a stretch with the 85gr Barnes if you accept an operating pressure of 55,000psi. I personally think 53,000psi should be the limit for the 6.8 based on chamber wall thickness and hoop stress, but what do I know. The 85gr MPG with .229 G1 BC is basically a short range affair when looking at retained energy, no matter how fast you spit it out. Same for the 85gr TTSX with .246 BC. Would make a great little close-range hunting load, but loses gas really fast. If anyone is really looking at this as a selling point for the 6.8, I would suggest a comparison with 5.56 70gr TSX Brown Tip, which has a BC of .314, and is very lethal on 2-legged, as well as 4-legged targets. If you want to step up in terminal performance on game, making the AR15 a large game capable hunting platform, then turn around and be able to use the same carbine or rifle for shooting steel at distance, then the 6.5 Grendel makes much more sense to start looking at a different caliber. If I want high velocity, low BC, close-in terminal performance, I already have 5.56 NATO. With the 6.8, the slight loss of velocity from a shorter barrel is not as drastic as in the 5.56.
So you get real rifle performance from a sub gun sized package. 5.56 doesn't lose velocity drastically with barrel length reduction, contrary to what has been stated for years and years now by writers that failed to take a chronograph out and actually shoot some 5.56 from SBR's over it. An 11.5" 5.56 carbine has plenty of mv with 55gr M193, 62gr M855, and even the Mk.318 and 70gr TSX. |
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Posted: 8/20/2014 1:36:30 PM EDT
[#49]
As noted above, the Accurate load data is based on the SPC chamber which is notorious for overpressure.
The factory SSA 85TSX Tac load is 3150 fps out of a 16" 1/11 barrel with an SPCII chamber It develops ~2900 out of a 12" barrel. Well within pressure limits. I've chronoed that SSA load out of a 16" Cardinal Armory lightweight barrel and it matched the specs on the box pretty close (within 20 fps) with no swipes. http://forum.lwrci.com/viewtopic.php?t=2708&start=15 http://www.ar15.com/archive/topic.html?b=3&f=121&t=503776 http://www.ar15.com/forums/t_3_121/578790__ARCHIVED_THREAD____6_8_with_a_12_5_inch_barrel__carbine_or_mid_length_.html&page=1#i5581167 |
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Posted: 8/20/2014 1:57:30 PM EDT
[#50]
Quote HistoryQuoted:
As noted above, the Accurate load data is based on the SPC chamber which is notorious for overpressure. The factory SSA 85TSX Tac load is 3150 fps out of a 16" 1/11 barrel with an SPCII chamber It develops ~2900 out of a 12" barrel. Well within pressure limits. I've chronoed that SSA load out of a 16" Cardinal Armory lightweight barrel and it matched the specs on the box pretty close (within 20 fps) with no swipes. http://forum.lwrci.com/viewtopic.php?t=2708&start=15 http://www.ar15.com/archive/topic.html?b=3&f=121&t=503776 http://www.ar15.com/forums/t_3_121/578790__ARCHIVED_THREAD____6_8_with_a_12_5_inch_barrel__carbine_or_mid_length_.html&page=1#i5581167 30 rounds of 85gr TSX-Tac averaged 3227 out of my 18" Bison SPC II 1:11.... |
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