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Posted: 5/20/2021 7:09:11 PM EDT
Was thinking about a second upper for my AR, and these 2 calibers are on the table.
The 6.8 was around d for a bit before the 300 (at least commercially), but I feel like the 6.8 has kinda died out recently, at least with how hot 300 BLK is. Barrel length would be 12.5" for this upper, so take that into consideration. Would either of these do something the other won't? Does the 6.8 have the option of running subs? Or was that meant to be fun at full power? Thanks! |
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The round I selected would depend on what I wanted to do with the firearm. I would chose the 6.5 Grendel or new 6mm knock off of the Grendel over either of those two rounds. If I had to choose one of the listed rounds for a suppressed pistol used inside 75 yards, I would probably go with the 300 BLK.
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when I want to kill something I use my 6.8. 2600 fps with a 115 grain bonded SP for 1800 ftflbs energy. (18 inch ) works great with 12.5 inch and suppressor also.
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Totally different rounds, so choice depends on your use. The advantages of the 300blk are ability to get the most oomph out of a short barrel, and you can shoot subsonics for fun if you want. Personally I like it for plinking subs, and as a suppressed HD gun. There's not really any reason to go above 9-9.5" barrel, and personally I think 8.5" is the sweet spot. Without a suppressor the gun is not attractive at all to me.
6.8/6.5G will give you much greater range. This would be my choice for hunting applications. Both rounds are capable from a 12.5" barrel. Main advantage is increased range, along with a a greater selection of good hunting bullets I guess. I have both, and the 300blk w/ can sits by the bed at night, but I don't hunt with it anymore after some so-so results. 6.5G hammers hogs/deer and will reach out several hundred yards no problem, whereas 300blk starts falling off pretty hard around 150-200 yards. If I could only have one, I'd take the 6.5G/6.8SPC. |
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They are not even remotely related. Apples and oranges. What do you want from the gun?
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Not be a buzzkill but have you checked where you normally get ammo for these 2? Both are hard to find right now.
Like above said more info would be good. Hunting? Supressed? Range wanted in Yards? |
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Depends on application. If you want to shoot subsonics suppressed, get the .300.
If you want superior energy on target, get the 6.8. I've got four 6.8's, but only one .300. The .300 is for shooting subs. |
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Quoted: The round I selected would depend on what I wanted to do with the firearm. I would chose the 6.5 Grendel or new 6mm knock off of the Grendel over either of those two rounds. If I had to choose one of the listed rounds for a suppressed pistol used inside 75 yards, I would probably go with the 300 BLK. View Quote |
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If you want to venture to the wild side with subs, look into 9x39. KAK makes a great upper
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SBR, subs, suppressor, NV, IR, shooting something in the face at 50ft = 300BLK. If a single one of those variables is removed, then the 300 BLK is not what you want. 68 all day.
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I’ve had several friends ditch 300BO in favor of 6.8 or 6.5 for hunting. 300 just doesn’t reliably get the job done, ESPECIALLY with sub loads.
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I treat my 300blk as a sub 8" barrel 9mm replacement.
You technically can do 6.8 subsonic but it requires a Bison Armory barrel with their fast twist rate and you need to load the rounds. 200 grain subs though, if you go that path. |
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Quoted: Was thinking about a second upper for my AR, and these 2 calibers are on the table. The 6.8 was around d for a bit before the 300 (at least commercially), but I feel like the 6.8 has kinda died out recently, at least with how hot 300 BLK is. Barrel length would be 12.5" for this upper, so take that into consideration. Would either of these do something the other won't? Does the 6.8 have the option of running subs? Or was that meant to be fun at full power? Thanks! View Quote At 12.5", I would go 6.8 over .300blk. While BCM makes a 12.5" .300blk upper, at that length, it seems like 6.8 would give you more options range. But it really comes down to what you are planning to do with the rifle. |
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Thanks all for the advice / help.
I have to go 12.5" or longer due to the state I live in, so a shorter barrel will need a permanent muzzle device affixed (like an 11.5" + flash hider). My other upper is in 45ACP for up-close work, and I will eventually be picking up a can for it. At least that's my plan. The 300BLK would be nice, as it will run well with the suppressor (assuming I get the can eventually), but I feel like it would duplicate the effort of the 45ACP. 6.8 would allow me to use the platform to longer ranges than my current 45ACP, but has the somewhat drawback of suppressor use. Shooting ranges in my state are pretty much all indoor or 100 yard outdoor, so I'm not looking to shoot 500 yards. I do have a chassis 700 in 308 that I can use for that kind of work. Or I could just go vanilla and pick up a 223 like 95% of all the other AR's out there. Just figured since I wasn't invested in 223, I might as well try to get a little more out of the platform. |
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I have both, prefer the 6.8. I have a 12.5" and a 16". Great hunting round and suppresses well.
If you are just going to buy an upper, I would strongly recommend the 6.8. Not for performance, but so you DONT mix up the parts. 6.8 will need different mags, and it won't chamber in a 5.56. 300blk uses the same mags and WILL chamber in a 5.56, leading to a kaboom. |
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I got both and like them both for different reasons. Going night hunting suppressed the 300blk with subs gets taken. Going hunting during the day the 6.8 gets the grab due to superior firepower.
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I have been a 6.8 SPC fan for years now. I have a Noveske 6.8 SPCII and a seldom seen Ruger ranch rifle 6.8. I hunt and plink with both rifles and they both do very well. The Ruger is less accurate, but that is expected.
My hunting range is only out to 200 yards and mostly for white tail deer and hogs. 6.8 has performed very well within that range. However....it's like everyone has posted here...depends on what you are going to use it for. When 6.8 came out, it was like 300BO or any other "new" caliber. It was the latest and greatest....for a while, then it was dropped like a hot rock probably because there was an issue that was eventually corrected with the SPCII coming out. After probably 5,000 rounds I've never had any issues with 6.8. I like it. I buy ammo when it's cheap.....and that was 3 years ago. I only buy Hornady for my 6.8....and that's not necessarily cheap, but it's reliable, consistent, and accurate. Settle your mind and get both.....That's the easy decision. |
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Quoted: Thanks all for the advice / help. I have to go 12.5" or longer due to the state I live in, so a shorter barrel will need a permanent muzzle device affixed (like an 11.5" + flash hider). My other upper is in 45ACP for up-close work, and I will eventually be picking up a can for it. At least that's my plan. The 300BLK would be nice, as it will run well with the suppressor (assuming I get the can eventually), but I feel like it would duplicate the effort of the 45ACP. 6.8 would allow me to use the platform to longer ranges than my current 45ACP, but has the somewhat drawback of suppressor use. Shooting ranges in my state are pretty much all indoor or 100 yard outdoor, so I'm not looking to shoot 500 yards. I do have a chassis 700 in 308 that I can use for that kind of work. Or I could just go vanilla and pick up a 223 like 95% of all the other AR's out there. Just figured since I wasn't invested in 223, I might as well try to get a little more out of the platform. View Quote I don’t think a subsonic 300 gives you much that your 45acp upper doesn’t already provide. Is the BC of the bullet that much of plus for effective range on a blk? Certainly not in comparison to what a 6.8 can do in a short barrel I’d vote 6.8 |
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I would strongly recommend the 6.8. Not for performance, but so you DONT mix up the parts. View Quote This is a poor reason to choose one or the other. If you can't segregate 300 from 5.56, time for another hobby |
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Quoted: People make mistakes. You can only create systems to prevent most of them, not all. View Quote View All Quotes View All Quotes Quoted: Quoted: This is a poor reason to choose one or the other. If you can't segregate 300 from 5.56, time for another hobby People make mistakes. You can only create systems to prevent most of them, not all. Exactly. And it happens far more often than you would think. |
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Quoted: This is a poor reason to choose one or the other. If you can't segregate 300 from 5.56, time for another hobby View Quote View All Quotes View All Quotes Quoted: I would strongly recommend the 6.8. Not for performance, but so you DONT mix up the parts. This is a poor reason to choose one or the other. If you can't segregate 300 from 5.56, time for another hobby I once put a full mag of 9mm through a .357 Sig without knowing it until I was picking up the brass. That was at least 15 years ago. Guess I should have stopped shooting and sold off the collection at that point. It only takes once. I picked up the correct mag and the wrong gun that day. OP: I like my 6.8s. Never owned a .300. |
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Quoted: Thanks all for the advice / help. I have to go 12.5" or longer due to the state I live in, so a shorter barrel will need a permanent muzzle device affixed (like an 11.5" + flash hider). My other upper is in 45ACP for up-close work, and I will eventually be picking up a can for it. At least that's my plan. The 300BLK would be nice, as it will run well with the suppressor (assuming I get the can eventually), but I feel like it would duplicate the effort of the 45ACP. 6.8 would allow me to use the platform to longer ranges than my current 45ACP, but has the somewhat drawback of suppressor use. Shooting ranges in my state are pretty much all indoor or 100 yard outdoor, so I'm not looking to shoot 500 yards. I do have a chassis 700 in 308 that I can use for that kind of work. Or I could just go vanilla and pick up a 223 like 95% of all the other AR's out there. Just figured since I wasn't invested in 223, I might as well try to get a little more out of the platform. View Quote But what do you mean on the "drawback of suppressor use" re: 6.8? It'll be perfect with a suppressor, and still shootable without one. On the other hand If you don't have a can, then 300blk verges on pointless IMO. The beauty of 300blk is good velocity/suppression in very short barrels along with really quiet suppressed subs. No can = 300blk not really worth it, especially considered side-by-side with a 6.5G/6.8. |
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Quoted: I once put a full mag of 9mm through a .357 Sig without knowing it until I was picking up the brass. That was at least 15 years ago. Guess I should have stopped shooting and sold off the collection at that point. It only takes once. I picked up the correct mag and the wrong gun that day. OP: I like my 6.8s. Never owned a .300. View Quote Been shooting guns of all types for over 45 years and have never shot the wrong ammo in any of them soooo |
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To be fair, .300blk is more than "just" a subsonic weapon.
I'd still probably pick 6.8 over .300blk in a 12.5" upper...but .300blk is still pretty damn capable and would be running roughly +95% of full ammo velocity with low recoil and flash. (Do you even need a flash hider on a 12.5" barrel in .300blk?) I bet some of the faster 110grs would be breaking 2300fps. The problem is at that barrel length, pretty much every other caliber starts to come into play. If you can have a can, 12.5" 5.56 middy would be really nice. |
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You won't need new magazines going with .300 Blackout.
Most of the rifles being blown up lately are people loading .300 Blackout in 5.56mm chambers by mistake. So there is that. 6.8 and 6.5 calibers are the hardest to find during panic buying. I would consider getting another 5.56mm until things resolve in the marketplace. |
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If you are going to suppress it and shoot subs, 300blk. If not and you just want mo powa, then 6.8 all the way.
I have both. |
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Quoted: Been shooting guns of all types for over 45 years and have never shot the wrong ammo in any of them soooo View Quote View All Quotes View All Quotes Quoted: Quoted: I once put a full mag of 9mm through a .357 Sig without knowing it until I was picking up the brass. That was at least 15 years ago. Guess I should have stopped shooting and sold off the collection at that point. It only takes once. I picked up the correct mag and the wrong gun that day. OP: I like my 6.8s. Never owned a .300. Been shooting guns of all types for over 45 years and have never shot the wrong ammo in any of them soooo So you're perfect. Must be nice. It's happened to me once in about 40 years of shooting. Two Sig P226s, one in 9mm and one in .357. |
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I've been shooting 6.8 since about 2007 or so. I have a 300 BO as well.
The 6.8 is fantastic. I only use my 300 as a toy to shoot suppressed subs. For my uses, it is good for little else. My 6.8 does everything better, except shoot subs. |
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Quoted: I've been shooting 6.8 since about 2007 or so. I have a 300 BO as well. The 6.8 is fantastic. I only use my 300 as a toy to shoot suppressed subs. For my uses, it is good for little else. My 6.8 does everything better, except shoot subs. View Quote Same here, and as posted by others. Other than shooting hogs at close range (75 yards max) and playing with subs on steel, I have no use for the .300 BO. Not saying it's not a good round for other things, I just have no interest beyond subs. |
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Quoted: Same here, and as posted by others. Other than shooting hogs at close range (75 yards max) and playing with subs on steel, I have no use for the .300 BO. Not saying it's not a good round for other things, I just have no interest beyond subs. View Quote View All Quotes View All Quotes Quoted: Quoted: I've been shooting 6.8 since about 2007 or so. I have a 300 BO as well. The 6.8 is fantastic. I only use my 300 as a toy to shoot suppressed subs. For my uses, it is good for little else. My 6.8 does everything better, except shoot subs. Same here, and as posted by others. Other than shooting hogs at close range (75 yards max) and playing with subs on steel, I have no use for the .300 BO. Not saying it's not a good round for other things, I just have no interest beyond subs. I'm the same. 6.8 does everything I need but I am going to play with the 6mm ARC. |
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Quoted: when I want to kill something I use my 6.8. 2600 fps with a 115 grain bonded SP for 1800 ftflbs energy. (18 inch ) works great with 12.5 inch and suppressor also. View Quote This. 300BO becomes almost useless past 150 yards and subs long before that. The 6.8 was designed to hit hard at 300 but drops off quickly afterwards. 300 uses all the same parts and accessories as 5.56, except the barrel. 6.8 uses different bolt, barrel and mags. |
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With steel case 300BLK ammo in the market now, 300BLK will be much more affordable to shoot. 6.5G got its popularly when steel case became available.
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Quoted: This. 300BO becomes almost useless past 150 yards and subs long before that. The 6.8 was designed to hit hard at 300 but drops off quickly afterwards. 300 uses all the same parts and accessories as 5.56, except the barrel. 6.8 uses different bolt, barrel and mags. View Quote Almost useless might be a touch of an overstatement....although part of that depends on barrel length and what you are shooting at. As much as I hate this cliche, I'm pretty sure no one wants to stand 200 yards down range wearing IIIA armor and take one to the chest from a 9". But if you are hunting whitetails...yeah....other calibers like 6.8 are much better. With that said, a good chunk of deer are taken, and all justified self defense shootings happen, within 150 yards. |
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Quoted: With steel case 300BLK ammo in the market now, 300BLK will be much more affordable to shoot. 6.5G got its popularly when steel case became available. View Quote I didn't even know that this was a thing so I had to Google it and sure enough it shows Barnaul manufacturing it. This might actually get me to be interested in 300 BO if things ever get back to normal. |
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Quoted: I’ve had several friends ditch 300BO in favor of 6.8 or 6.5 for hunting. 300 just doesn’t reliably get the job done, ESPECIALLY with sub loads. View Quote I disagree, based on my personal experience. Here is just one of the few Black Bear my son has shot with his 300BO using 110TTSX handloads. All shot around 100 yards. All clean pass through the vitals, and none ran more than 20 yards before expiring. It's an excellent hunting round and more than capable to taking game reliably at appropriate distances. 6.8 will give you another 100 yards of reliable expansion, but at those ranges you should be stepping up from an intermediate cartridge and getting into a high powered rifle cartridge anyways. Just my .2 OP have you checked out 6.8 ammo and components lately? 300BO is tough to find as it is. Even for a handloader 6.8 components are barely existant. Not taking a thing away from the cartridge, it's very cool and viable in it's own niche, but these days, and for the near future ammo/component availability is a huge factor when deciding what cartridge you want to shoot. Attached File |
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Out of a 12” barrel 6.8 will have more capability and range than .300 Blackout. That’s a good barrel length for 5.56, 6.5 Grendel, and 6.8. The latter two are easily max point blank range hunting guns, with at least 50-100 yards more reach than a 16” Blackout with it’s best bullet, depending on game.
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Quoted: Thanks all for the advice / help. I have to go 12.5" or longer due to the state I live in, so a shorter barrel will need a permanent muzzle device affixed (like an 11.5" + flash hider). My other upper is in 45ACP for up-close work, and I will eventually be picking up a can for it. At least that's my plan. The 300BLK would be nice, as it will run well with the suppressor (assuming I get the can eventually), but I feel like it would duplicate the effort of the 45ACP. 6.8 would allow me to use the platform to longer ranges than my current 45ACP, but has the somewhat drawback of suppressor use. Shooting ranges in my state are pretty much all indoor or 100 yard outdoor, so I'm not looking to shoot 500 yards. I do have a chassis 700 in 308 that I can use for that kind of work. Or I could just go vanilla and pick up a 223 like 95% of all the other AR's out there. Just figured since I wasn't invested in 223, I might as well try to get a little more out of the platform. View Quote 6.8 is the perfect match for you. |
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I think of 300BLK as a MP5SD replacement with greater range and terminal ballistics if things go bad. Like many others have said, 8-9" barrels and suppressed.
6.8SPC kills stuff way better. I don't believe in trying to kill game with the smallest/weakest possible caliber to say it can be done. I like to drop things pretty quick and not have them run off and bleed out where I can't find them. |
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Quoted: Thanks all for the advice / help. I have to go 12.5" or longer due to the state I live in, so a shorter barrel will need a permanent muzzle device affixed (like an 11.5" + flash hider). My other upper is in 45ACP for up-close work, and I will eventually be picking up a can for it. At least that's my plan. The 300BLK would be nice, as it will run well with the suppressor (assuming I get the can eventually), but I feel like it would duplicate the effort of the 45ACP. 6.8 would allow me to use the platform to longer ranges than my current 45ACP, but has the somewhat drawback of suppressor use. Shooting ranges in my state are pretty much all indoor or 100 yard outdoor, so I'm not looking to shoot 500 yards. I do have a chassis 700 in 308 that I can use for that kind of work. Or I could just go vanilla and pick up a 223 like 95% of all the other AR's out there. Just figured since I wasn't invested in 223, I might as well try to get a little more out of the platform. View Quote A 12.5" suppressed 6.8 makes a great deer rifle for around here. I like mine quite a bit. However, outside of hunting season it stays home most of the time. I put together a very similar rifle in 5.56 with the same trigger, stock, optic, etc. Both are suppressed but neither is hearing safe. The 5.56 is much cheaper to shoot in normal times. |
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I have shot 6.8 out to 500 from an 11.3” Wilson Combat barrel with great results. I load and shoot 300BO because it is fun to play with, but at distance it won’t ever be like 6.8.
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Why are you going with 6.8 SPC over 6.5 Grendel? I dont recall the exact source of the info, but I believe they were both very close with 6.5 Grendel doing better out of a 12.5" barrel. At the time, 6.5 Grendel components were also more available and had a greater selection of bullets. I went with a 6.5 Grendel in a 12.5" SBR. I also have an 8" 300 blk out that I love. All of my guns are suppressed. The 300blk has fantastic ballistics and maneuverability in an 8" barrel and there are excellent choices for bullets. After seeing ANOTHER ammo shortage I invested into loading my own. That being said I believe 6.5 Grendel has more support from ammunition manufacturers compared to 6.8.
I wouldnt be getting into boutique calibers right now if your dependent on off the shelf ammo. A system is only as good as the ammo your using. If you can't get ammo and practice with it and dial it in with a specific round it seems kind of silly to think you're going to build something that's accurate to 350+ yards. Do you have optics that match the capabilities of 6.5 or 6.8? Do you have a decent trigger? You can get the nicest 6.5 or 6.8 upper you want, but if you can only find 1 box of this ammo or one box of that ammo here and there, you've got a mil-spec LPK trigger and a red dot then you are absolutely wasting your time. An equivalent barrel length 556 with a nice trigger, capable glass, and MK262 clone ammo will embarrass you from even a novice shooter. Be realistic about the total cost. Distance takes money and practice. |
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