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Posted: 6/27/2017 10:57:51 PM EDT
[#1]
http://www.ar15.com/forums/t_3_16/503947_AR15-Ammo-Forum-FAQ.html
#1 in the above link: http://www.ar15.com/ammo/project/Self_Defense_Ammo_FAQ/index.htm Have you read everything in that #1 article? |
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Posted: 6/28/2017 12:26:51 AM EDT
[#2]
When I picked my SD loads for 5.56, I looked at which rounds were designed to expand at what velocities, their muzzle velocity, accuracy in my rifles, etc. Considering that 5.56 is already at a disadvantage to .308 and 6.5, this was a very important consideration to me.
Most of the FMJ loads aren't designed to fragment, even if they will (sometimes) at higher velocity. Take for instance either M193 or M855 loads. They're designed for "humane" warfare, whatever that means, and a plethora of tests available pretty much everywhere says that they wouldn't do much more than drill a .223 sized hole under 2700 fps. To try to answer your question comparing fragmenting loads to bonded ones, a proper bonded bullet will offer an expansion threshold down to 1800-1900 fps, greatly extending the range at which you're capable of inflicting more damage. A far as your comparison of rifle and pistol rounds, the best answer I can give you is that pistol rounds can be extremely devastating at close range but pistols are just that, close range weapons. If there was such a thing as gel tests directly comparing a rifle and pistol shot at 100yds, the rifle would win every measurement, every time (once again speaking generally). Whatever ammo you settle on, its important to practice with it because regardless of the load in .223/5.56, shot placement is going to be an important factor in stopping a threat. |
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Posted: 6/28/2017 7:14:24 AM EDT
[#3]
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Posted: 6/28/2017 10:16:18 AM EDT
[#4]
Watch some videos of rifle and pistol shots into ballistic gelatin. The thing you're missing is that the permanent cavity from a high-power rifle round isn't limited to the expanded diameter of the bullet, like it is with a slower pistol round. A .45 that expands to .510 will bore a .510" hole through the target and that's the diameter of the permanent cavity; a .224" rifle bullet going 2500fps will create a permanent cavity of destroyed tissue several inches across.
As for expanding v. fragmenting, that's a bit of personal preference. Given proper impact velocity, IMO a bullet designed to expand will probably expand more reliably, as compared to how reliably a bullet that relies on fragmentation will fragment. A 55gr TSX will pretty much always expand the way it should if it's going over 2000fps; XM193 might fragment, might not. |
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Posted: 6/28/2017 12:36:10 PM EDT
[#5]
Quote HistoryQuoted:
just get these |
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Posted: 6/28/2017 2:03:09 PM EDT
[#6]
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**As long as you're not shooting it out of a short SBR.** Quote HistoryQuoted:
Quoted:
just get these |
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Posted: 6/28/2017 2:23:12 PM EDT
[#7]
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Well, based on your tests, Eagle, (thanks again!) if you are shooting an SBR in a CQB battle (like in a house), I think this round is good. But I agree that once you get beyond 50 - 75 yards or so, it may be just an "ice pick" bullet. I don't have a shot beyond 45 feet in my house, so I do have mags loaded with this round in case I need to shoot through a door/wall. My suppressed 10.5" SBR stays loaded with Hornady TAP T2, which is my primary defensive round of choice, but I will grab a magazine with GD 64's if I can. I believe 64GD would do very well in a CQB role from a 10.5"-11.5" barrel, though I am reserving my stash of it for longer barrels (14.5" and up) in favor of Fusion MSR or BH 77TMK. |
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Posted: 6/28/2017 2:27:16 PM EDT
[#8]
I looked at the chart, saw which were recommended for an SBR and then compared the list to what was available from sgammo. Bought one that matched. Test fired it in my gun.
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Posted: 6/28/2017 6:21:56 PM EDT
[#9]
Yes... several times. I know what the loads recommended are.
I know that they are barrier penetrating rounds with high weight retention that offer expansion and the recommend penetration depth of 12 to 18 inches... but I have also read that human tissue is far more elastic then gel is so the stretch damage for ordnance gelatin would not have the same effect on living tissue.... So if that's the case then a .45 acp hornady critical duty round expands to .70 and offers 14 inches of penetration... a .223 64 grain gold dot expands to .46 and offers 14 inches of penetration. What is the reason the rifle is more effective? Its not just because it has "more energy"... So I am assuming that the higher velocity of a rifle round displaces tissue at a rate that causes damage to an area greater then the surface diameter of the projectile.... which is listed at approx. 2000 fps needed.... Is that figure correct? If that's the case then why is a 7.62 x 39 round recommended in a short barrel when it may not achieve that velocity beyond 25 yds? |
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Posted: 6/28/2017 6:27:49 PM EDT
[#10]
Quote HistoryQuoted:
When I picked my SD loads for 5.56, I looked at which rounds were designed to expand at what velocities, their muzzle velocity, accuracy in my rifles, etc. Considering that 5.56 is already at a disadvantage to .308 and 6.5, this was a very important consideration to me. Most of the FMJ loads aren't designed to fragment, even if they will (sometimes) at higher velocity. Take for instance either M193 or M855 loads. They're designed for "humane" warfare, whatever that means, and a plethora of tests available pretty much everywhere says that they wouldn't do much more than drill a .223 sized hole under 2700 fps. To try to answer your question comparing fragmenting loads to bonded ones, a proper bonded bullet will offer an expansion threshold down to 1800-1900 fps, greatly extending the range at which you're capable of inflicting more damage. A far as your comparison of rifle and pistol rounds, the best answer I can give you is that pistol rounds can be extremely devastating at close range but pistols are just that, close range weapons. If there was such a thing as gel tests directly comparing a rifle and pistol shot at 100yds, the rifle would win every measurement, every time (once again speaking generally). Whatever ammo you settle on, its important to practice with it because regardless of the load in .223/5.56, shot placement is going to be an important factor in stopping a threat. |
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Posted: 6/28/2017 6:30:53 PM EDT
[#11]
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So I am assuming that the higher velocity of a rifle round displaces tissue at a rate that causes damage to an area greater then the surface diameter of the projectile.... which is listed at approx. 2000 fps needed.... Is that figure correct? |
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Posted: 6/28/2017 6:31:35 PM EDT
[#12]
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**As long as you're not shooting it out of a short SBR.** |
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Posted: 6/28/2017 6:33:03 PM EDT
[#13]
Quote HistoryQuoted:
http://www.ar15.com/forums/t_3_16/503947_AR15-Ammo-Forum-FAQ.html #1 in the above link: http://www.ar15.com/ammo/project/Self_Defense_Ammo_FAQ/index.htm Have you read everything in that #1 article? I know that they are barrier penetrating rounds with high weight retention that offer expansion and the recommend penetration depth of 12 to 18 inches... but I have also read that human tissue is far more elastic then gel is so the stretch damage for ordnance gelatin would not have the same effect on living tissue.... So if that's the case then a .45 acp hornady critical duty round expands to .70 and offers 14 inches of penetration... a .223 64 grain gold dot expands to .46 and offers 14 inches of penetration. What is the reason the rifle is more effective? Its not just because it has "more energy"... So I am assuming that the higher velocity of a rifle round displaces tissue at a rate that causes damage to an area greater then the surface diameter of the projectile.... which is listed at approx. 2000 fps needed.... Is that figure correct? If that's the case then why is a 7.62 x 39 round recommended in a short barrel when it may not achieve that velocity beyond 25 yds? |
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Posted: 6/28/2017 6:35:21 PM EDT
[#14]
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Good luck getting a definitive answer on that. Quote HistoryQuoted:
Quoted:
So I am assuming that the higher velocity of a rifle round displaces tissue at a rate that causes damage to an area greater then the surface diameter of the projectile.... which is listed at approx. 2000 fps needed.... Is that figure correct? |
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Posted: 6/28/2017 6:39:37 PM EDT
[#15]
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Well its either a closely guarded secret or know one knows.... So if know one knows, then how does anyone know what to recommend in that velocity range? I've read so many conflicting articles on the subject that my head hurts. If someone knows the minimum formula to achieve a permanent stretch cavity, please chime in. |
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Posted: 6/28/2017 6:50:06 PM EDT
[#16]
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I'd say the latter. I've read so many conflicting articles on the subject that my head hurts. If someone knows the minimum formula to achieve a permanent stretch cavity, please chime in. Quote HistoryQuoted:
Quoted:
Well its either a closely guarded secret or know one knows.... So if know one knows, then how does anyone know what to recommend in that velocity range? I've read so many conflicting articles on the subject that my head hurts. If someone knows the minimum formula to achieve a permanent stretch cavity, please chime in. It would stand to reason that the larger projectile would offer a lower fps threshold then the smaller .223... So that's why I want to know where the difference becomes apparent. Im trying to decide on a caliber and barrel length... Basically I want better then pistol ballistics out to 100 yds in the smallest package possible. I would prefer the lower cost of .223 vs 6.8 spc.... I want to know if the extra expense of 6.8 spc is worth the increase in performance inside of 100 yds... or if I can get acceptable performance out of commercial .223/5.56 rounds at that distance at a lower cost.... Which would mean that I could actually practice with the rifle 2X as ofter |
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Posted: 6/28/2017 6:58:15 PM EDT
[#17]
I think the issue with the shorter 5.56, is that it may not provide the velocity needed for the ultra popular 55g fmj (m193) to upset which is required to make the round lethal.
I believe that is around 2700fps. I'm of the belief that velocity is only part of the equation when it comes to creating a permanent stretch cavity. I think bullet mass/diameter factors in as well. I've been told many times that I was wrong thinking that though. |
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Posted: 6/28/2017 7:03:17 PM EDT
[#18]
Penetration is always number 1 for me. If a round fails to go 12-18" deep, then it's no good. I personally prefer something closer to the 18" mark. And of course what kind of permanent and temporary cavities it makes. Permanent cavities are more important to me. Something like 5.56mm I prefer heavier rounds like 75 or 77 grain rounds. For 30 caliber rounds like 7.62x39mm or 300BLK or 308 I prefer something with a ballistic tip. But yeah rifle rounds need to be over 2,000FPS to act like a rifle round. Under 2,000FPS and it's going to act like a handgun round and just punch right through like a stab wound. Also 7.62x39mm out of 16" is going over 2,000FPS for sure!! That would be some really weak ammo if it went lower than 2,000FPS, haha. It's usually more like 2350FPS or so.
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Posted: 6/28/2017 7:07:38 PM EDT
[#19]
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Penetration is always number 1 for me. If a round fails to go 12-18" deep, then it's no good. I personally prefer something closer to the 18" mark. And of course what kind of permanent and temporary cavities it makes. Permanent cavities are more important to me. |
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Posted: 6/28/2017 8:15:45 PM EDT
[#20]
Quote HistoryQuoted:
Penetration is always number 1 for me. If a round fails to go 12-18" deep, then it's no good. I personally prefer something closer to the 18" mark. And of course what kind of permanent and temporary cavities it makes. Permanent cavities are more important to me. Something like 5.56mm I prefer heavier rounds like 75 or 77 grain rounds. For 30 caliber rounds like 7.62x39mm or 300BLK or 308 I prefer something with a ballistic tip. But yeah rifle rounds need to be over 2,000FPS to act like a rifle round. Under 2,000FPS and it's going to act like a handgun round and just punch right through like a stab wound. Also 7.62x39mm out of 16" is going over 2,000FPS for sure!! That would be some really weak ammo if it went lower than 2,000FPS, haha. It's usually more like 2350FPS or so. Im not trying to create an argument.... If its the better choice and I know why its the better choice It will help me to decide if that reason comes into play for my intended use |
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Posted: 6/28/2017 8:27:15 PM EDT
[#21]
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I think most here would not argue with that, but what is actually needed to create a permanent stretch cavity is what I believe the op is looking for. SWAT teams no longer use mp5's... they use rifles now. If the targets they shoot at are across the room, the added range of a rifle is irrelevant... So the switch from 9mm to 5.56 must be a performance based switch otherwise the depts. wouldn't spend the money to outfit the officers with the new weapons.... but if both require equally well placed shots that pass through vitals... at close range it would be equally difficult and the target would be equally dead either way... So the rifle has to add a benefit over the MP5 at the close ranges a police officer would encounter or they would still be using MP5's. As a civilian a defensive weapon for me would be used at similar distances as a police officer that now uses a rifle round over a pistol round and my reasons for wanting a more effective weapon then a pistol would be the same as theirs. Since they now use rifles even in close quarters .... It stands to reason that a rifle offers something an MP5 does not, I assume its being more effective... I want to know at what velocity it ceases being more effective and/or what it is about the rifle rounds design function that gives it an advantage... Then I will be able to know which round will offer that same advantage to me, at what distances I can expect for it to do so, and which caliber and barrel length is needed |
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Posted: 6/28/2017 8:39:46 PM EDT
[#22]
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Yes that's my exact reason for asking.... I what to know which rounds will offer performance at various distances, and what to expect performance wise... since there are rounds designed to expand down to 1600 fps... at what velocity does the faster, but smaller expanded diameter rifle round begin to lose its advantage to the slower but larger expanded diameter pistol round? |
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Posted: 6/28/2017 8:43:18 PM EDT
[#23]
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Take a look at the 6th post in my velocity test thread. It lists ballistics tables for many common SD rounds. For pretty much anything in the M193 or M855 classes, keep 2700fps in mind for fragmentation threshold. Quote HistoryQuoted:
Quoted:
Yes that's my exact reason for asking.... I what to know which rounds will offer performance at various distances, and what to expect performance wise... since there are rounds designed to expand down to 1600 fps... at what velocity does the faster, but smaller expanded diameter rifle round begin to lose its advantage to the slower but larger expanded diameter pistol round? the muzzle velocity range Im looking at is approx. 2200 or 2300... So I can use a ballistics calculator to know what my velocity will be at the intended range of 100 yds or less... but without understanding what a bullet needs to do and how fast it needs to be doing it I cant tell if the .223 will work for those ranges or if I need to use the 6.8 instead and have to just deal with the more expensive rounds |
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Posted: 6/28/2017 8:46:36 PM EDT
[#24]
That's cool, I would never want to shoot them from a shorty either.
ETA: except for practice... |
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Posted: 6/28/2017 8:46:40 PM EDT
[#25]
Oh I understand your question now. Yeah for short barrels 300BLK is king because it is designed for 9" barrels. While 7.62x39mm was designed for 16" barrels, and 5.56mm designed for 20" barrels. The reason 300BLK is awesome in short barrels is because it uses pistol powder instead of rifle powder. Handgun powder burns at a much faster rate compared to rifle powder. So a short barreled 5.56mm or 7.62x39mm round kind of sucks compared to 300BLK. The 300BLK burns up all it's gun powder in the short barrel getting the round to good speeds. While the 5.56mm and 7.62x39mm rounds are still burning a lot of it's rifle powder outside after the round left the barrel, making them louder and less effective. For home defense/hunting in a SBR suppressed setup the 300BLK is sweet!! Like my 110 grain rounds are doing around 2300FPS out of an 8" barrel. Basically the same ballistics as the AK round, but out of a much shorter barrel.
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Posted: 6/28/2017 8:53:01 PM EDT
[#26]
This topic is incredibly useful however what is the best 223/556 round to opt for out of a 16" barrel? I see a ton of Speer Gold Dot 64gr recommendations along with Hornady TAP. My Glock 17 is my primary right now but I'm looking to equip my ARs with the proper ammunition for the SHTF situation. Thought?
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Posted: 6/28/2017 8:53:39 PM EDT
[#27]
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Oh I understand your question now. Yeah for short barrels 300BLK is king because it is designed for 9" barrels.....<snip> .....For home defense/hunting in a SBR suppressed setup the 300BLK is sweet!! |
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Posted: 6/28/2017 8:54:32 PM EDT
[#28]
Quote HistoryQuoted:
Oh I understand your question now. Yeah for short barrels 300BLK is king because it is designed for 9" barrels. While 7.62x39mm was designed for 16" barrels, and 5.56mm designed for 20" barrels. The reason 300BLK is awesome in short barrels is because it uses pistol powder instead of rifle powder. Handgun powder burns at a much faster rate compared to rifle powder. So a short barreled 5.56mm or 7.62x39mm round kind of sucks compared to 300BLK. The 300BLK burns up all it's gun powder in the short barrel getting the round to good speeds. While the 5.56mm and 7.62x39mm rounds are still burning a lot of it's rifle powder outside after the round left the barrel, making them louder and less effective. For home defense/hunting in a SBR suppressed setup the 300BLK is sweet!! Like my 110 grain rounds are doing around 2300FPS out of an 8" barrel. Basically the same ballistics as the AK round, but out of a much shorter barrel. Thanks... 2300 fps I would be thrilled with from a .30 cal projectile... I have seen how well they do. I haven't seen many 5.56 examples at the similar speeds.. are those factory or handloads? |
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Posted: 6/28/2017 8:56:23 PM EDT
[#29]
Quote HistoryQuoted:
This topic is incredibly useful however what is the best 223/556 round to opt for out of a 16" barrel? I see a ton of Speer Gold Dot 64gr recommendations along with Hornady TAP. My Glock 17 is my primary right now but I'm looking to equip my ARs with the proper ammunition for the SHTF situation. Thought? |
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Posted: 6/28/2017 8:58:42 PM EDT
[#30]
Quote HistoryQuoted:
This topic is incredibly useful however what is the best 223/556 round to opt for out of a 16" barrel? I see a ton of Speer Gold Dot 64gr recommendations along with Hornady TAP. My Glock 17 is my primary right now but I'm looking to equip my ARs with the proper ammunition for the SHTF situation. Thought? |
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Posted: 6/28/2017 9:01:23 PM EDT
[#31]
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<snip> Like my 110 grain rounds are doing around 2300FPS out of an 8" barrel. Basically the same ballistics as the AK round, but out of a much shorter barrel. |
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Posted: 6/28/2017 9:04:45 PM EDT
[#32]
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This is the best answer. I have three short 300BLK guns, two SBR and one pistol. 8" pistol is my truck gun, 8" SBR is my bedside gun, 10.5" SBR is my "woodland" deer hunting rifle. Quote HistoryQuoted:
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Oh I understand your question now. Yeah for short barrels 300BLK is king because it is designed for 9" barrels.....<snip> .....For home defense/hunting in a SBR suppressed setup the 300BLK is sweet!! It looks like its a case of pick two...Cheap ammo, small rifle, effective ballistics |
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Posted: 6/28/2017 9:07:33 PM EDT
[#33]
Why not 300BLK?
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Posted: 6/28/2017 9:10:50 PM EDT
[#34]
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Im interested in having the smallest rifle possible... neither of those rounds would work for my intended use the muzzle velocity range Im looking at is approx. 2200 or 2300... I've seen videos of the 64g GD expanding at 1900fps (albeit a rather long neck) out of a 7.5" and Blue Falcon has tested the Fusion MSR's down to 1700fps with expansion, so both rounds will do the job at up to your 100yrd max distances. As for whether or not those 1700-2300fps velocities with a .223 sized projectile (.45 after expansion) are enough to create a wound greater than the size of the expanded bullet (permanent stretch cavity), I cant answer. A bullet loses velocity abruptly at impact and especially after expansion. So if there is a magical velocity # that will permanently stretch the internals, I would imagine that would have to be figured into it as well. |
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Posted: 6/28/2017 9:17:58 PM EDT
[#35]
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Why not 300BLK? |
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Posted: 6/28/2017 9:24:49 PM EDT
[#36]
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That's about the MV you would get with a 10.5" and Gold Dots and Fusions. I've seen videos of the 64g GD expanding at 1900fps (albeit a rather long neck) out of a 7.5" and Blue Falcon has tested the Fusion MSR's down to 1700fps with expansion, so both rounds will do the job at up to your 100yrd max distances. As for whether or not those 1700-2300fps velocities with a .223 sized projectile (.45 after expansion) are enough to create a wound greater than the size of the expanded bullet (permanent stretch cavity), I cant answer. A bullet loses velocity abruptly at impact and especially after expansion. So if there is a magical velocity # that will permanently stretch the internals, I would imagine that would have to be figured into it as well. |
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Posted: 6/28/2017 9:33:55 PM EDT
[#37]
Right on, I checked out the link to PSA someone had posted...Gold Dots for 9.99/box of 20? Um yes I'll take several. Grabbed some D&H mags as well. Thanks guys!
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Posted: 6/28/2017 9:34:49 PM EDT
[#38]
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Well... if there is that 2000 fps velocity rule for what is needed from a rifle... most under 10.5 inch barrel 300 blk velocity tests I have seen would fall under that at 50 yds or less... an 85 or 90 grain 6.8spc will triple that range in an equal barrel length |
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Posted: 6/28/2017 9:35:10 PM EDT
[#39]
Out of SBRs, I prefer the Black Hills 5.56mm 50 gr TSX load.
 Why 50gr TSX Is The Ultimate 5.56mm Home Defense Load: Black Hills 5.56mm 50gr TSX Gel Test But in .223/5.56, I try to stick with 11.5" barrels for SBR/pistols, 10.5" at the bare minimum. Anything smaller than that and I'm going with .300 BLK. Once you move on up to 14.5" or 16" barrel lengths, you have a lot more options for good defensive/shtf ammo. But many that will perform well from a 16" barrel won't perform very well out of the really short barrels, especially as ranges increase. |
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Posted: 6/28/2017 9:56:44 PM EDT
[#40]
OP, check out the guy in the last post of my thread here that took a deer at 175yrds with a 300BO.
Granted he was using a 16" barrel, but I'm estimating the impact velocity was around 1850-1875 fps. Plenty of guys taking out medium deer and pigs up to 150 yards with 8-9" 300bo that aren't hitting any where near that 2000fps mark at impact. |
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Posted: 6/29/2017 12:43:11 AM EDT
[#41]
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my opinion, but I wouldn't be stuck on that 2000fps rule. If barrier/ bonded loads that expand and stay intact and penetrate 12 to 18 inches are recommended... They would have to cause damage larger then the projectile for that to make sense... If its just the tissue in the projectiles path that is affected a .45 acp round expands to a larger diameter and offers equal penetration.... So a .45 is bigger, heavier and penetrates to the same depth as a .223.... the only thing a .223 bonded, expanding round does that a .45 acp doesn't.... is go really fast. Since no one is using Thompson SMG's and they are using .223's... the recommended .223 loads expand but don't fragment... the only thing that's left that a .223 does is go fast. how fast does it have to be travelling before the .223's higher velocity loses its advantage to .45 acp's greater mass? If I knew what the approx. threshold was, I would be able to see what rounds would exceed that threshold out to at least 100 yds from the velocity produced by an 8.5 inch 5.56 barrel. Without knowing that threshold ,I really don't think that I would have confidence in that sized barrel if I don't know where it becomes less effective then a pistol round of a larger size.... So im going to go either 6.8 or 10.5 inch... To me... 300 blk supersonics in an 8.5 inch barrel don't do anything that a 6.8 spc doesn't do better from an 8.5, and the 300 blk suffers from the same concerns I have for the slower then ideal velocities of the 5.56 would also plague the even slower 300 blk |
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Posted: 6/29/2017 5:24:32 AM EDT
[#42]
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Are those handloads? I get just over 2100fps with Barnes 110gr TAC-TX from both my 8" barrels. This is based off my own experience chronographing both my own handloads and factory loads in a 16 and 10" bbl. |
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Posted: 6/29/2017 6:13:38 PM EDT
[#43]
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There's no way a factory 110gr load is hitting 2300 IMO from an 8". This is based off my own experience chronographing both my own handloads and factory loads in a 16 and 10" bbl. Quote HistoryQuoted:
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Are those handloads? I get just over 2100fps with Barnes 110gr TAC-TX from both my 8" barrels. This is based off my own experience chronographing both my own handloads and factory loads in a 16 and 10" bbl. off topic... is there any reason I coundn't use a 1 in 8 twist 8.5 inch barrel with 6.8 spc supersonics? Typically the twist rate is 1 in 12 but as far as I know you cant really "over stabilize" a bullet and a faster twist rate isn't an issue except if the bullet is a very lightly jacketed one. |
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Posted: 6/29/2017 8:55:43 PM EDT
[#44]
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I didn't think so... "the chopping block" had the highest I have seen and that was just over 2200. Us guys at sea level benefit with the thicker air helping increase HP in our gassers, but suffer some bullet velocity loss because of it. I usually get between 2030-2060 fps with the 110g Tac-tx in my 8". |
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Posted: 6/29/2017 9:44:19 PM EDT
[#45]
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Well its not just 2000 fps so much as it is what impact velocity is needed for tissue damage larger then the projectile.... Maybe this is a better way of putting it.... If barrier/ bonded loads that expand and stay intact and penetrate 12 to 18 inches are recommended... They would have to cause damage larger then the projectile for that to make sense... If its just the tissue in the projectiles path that is affected a .45 acp round expands to a larger diameter and offers equal penetration.... So a .45 is bigger, heavier and penetrates to the same depth as a .223.... the only thing a .223 bonded, expanding round does that a .45 acp doesn't.... is go really fast. Since no one is using Thompson SMG's and they are using .223's... the recommended .223 loads expand but don't fragment... the only thing that's left that a .223 does is go fast. how fast does it have to be travelling before the .223's higher velocity loses its advantage to .45 acp's greater mass? If I knew what the approx. threshold was, I would be able to see what rounds would exceed that threshold out to at least 100 yds from the velocity produced by an 8.5 inch 5.56 barrel. Without knowing that threshold ,I really don't think that I would have confidence in that sized barrel if I don't know where it becomes less effective then a pistol round of a larger size.... So im going to go either 6.8 or 10.5 inch... To me... 300 blk supersonics in an 8.5 inch barrel don't do anything that a 6.8 spc doesn't do better from an 8.5, and the 300 blk suffers from the same concerns I have for the slower then ideal velocities of the 5.56 would also plague the even slower 300 blk I know some people say that kinetic energy doesnt really matter, while some say that it doesn't really matter unless its 700ft.#'s or more. I can tell you this, water jugs take a hell of a lot more beating from my 2050fps 110g barnes (1025ft.lbs) rounds than they do from 147G HST (330ft.lbs?) from my G19. Hell, even the anemic remington otm's, moving less than 1900fps (~940ft.lbs), shred the jugs way more than any of my pistol rounds. |
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Posted: 7/1/2017 4:50:31 PM EDT
[#46]
I like a barrier-blind round because it is effective in more situations. For a rifle I like at least 16in penetration, and I like the round to perform well through auto-glass.
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Posted: 7/3/2017 6:27:22 PM EDT
[#47]
before I got too worked over muzzle velocity from SBRs and expansion/tissue damage etc. I'd make sure I was capable of making accurate hits in lethal areas and then once that was achieved then I would pick a round that would give decent penetration through barrier or not. seems everyone gets so into discussing what bullets do which and at what velocities, they forget they still have to hit a vital spot
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