User Panel
Posted: 3/28/2019 9:44:55 AM EDT
Are there any noticeable differences between a 10.5 in and a 11.5 in (FBI-type) AR pistol in terms of handling, performance, excess gas, wear and tear, etc.? This would not be a copy-cat build; just a general, all around AR pistol with a brace.
It seems like I've read on here that there were significant ballistic advantages brought by the extra inch (ib4 that's what she said) which led the FBI to adopt the 11.5 barrel length. What are GD's thoughts? |
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If your going to want to use mil speck ammo like XM193 I suggest 11.5" nothing shorter.
Frag range is shit in short barrels unless you use some kind of specialty ammo like Vmax. Also I'm assuming it's a 5.56 barrel. If your talking 9mm or something else then forget everything I said. |
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Cartridge Information5.56mm M193 55gr Ball with BC of .243
Fragmentation threshold2700 fps (20": 130 yd / 16": 105 yd / 14.5": 90 yd)11.5" 40m10.25" 14m RangeVelocity (ft/sec)Energy (ft-lbs) 20"16"14.5"20"16"14.5" 0325931323064129711981146 25314630232958120911161068 5030372919285511261040995 752932281727561050969928 100283027202661978903865 125273226252568911841805 150263725342479849784750 175254624462393792731699 200245723622310737681652 225237222802230687635607 250229022012153640592566 275221021242078596551527 300213420512006556514491 350198819111869483446427 400185317811742419387371 450172616591623364336322 500160915461513316292280 Fuck all formatting was lost on copy paste... |
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Here's a good read on velocity differences - linky
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10.3 used to be the hottness, then the cool kids starting using 11.5. Now people are starting to use 12.5 and eventually we'll all be back to the approved tactical length of 16".
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Quoted:
If your going to want to use mil speck ammo like XM193 I suggest 11.5" nothing shorter. Frag range is shit in short barrels unless you use some kind of specialty ammo like Vmax. Also I'm assuming it's a 5.56 barrel. If your talking 9mm or something else then forget everything I said. View Quote It's true, 11.5" means a lot more for standard military ammo damage on target. The 'cheat' that I now realize I can/could use - after years of looking at 11.5" builds, but not buying (instead went to a 10.5" 300 AAC) - is soft-point bonded jacket 5.56 ammo. Civilians aren't regulated by military rules, so ammo choice is crucial if going for a 10.5" barrel. AR15.COM 's Hornady Frontier 62gr SP Gel Test I'm still stuck, though - I still demand as light of a barrel as possible, and Palmetto State Armory doesn't offer 'pencil' barrels in their 10.5" uppers. I'd have to buy a Faxon or Ballistic Advantage lightweight 10.5" barrel to get what I want out of my next pistol upper. |
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Quoted: And I used to hold to this like concrete, but the facts are in the details (as StewartTR points toward by stating "If" using XM193-like ammo). It's true, 11.5" means a lot more for standard military ammo damage on target. The 'cheat' that I now realize I can/could use - after years of looking at 11.5" builds, but not buying (instead went to a 10.5" 300 AAC) - is soft-point bonded jacket 5.56 ammo. Civilians aren't regulated by military rules, so ammo choice is crucial if going for a 10.5" barrel. I'm still stuck, though - I still demand as light of a barrel as possible, and Palmetto State Armory doesn't offer 'pencil' barrels in their 10.5" uppers. I'd have to buy a Faxon or Ballistic Advantage lightweight 10.5" barrel to get what I want out of my next pistol upper. View Quote |
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I believe the frag range with M193 and a 10.5" barrel would be something like 14 meters if memory servers...
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I believe there is 40% more dwell time with the 11.5" over the 10.5", that made the decision for me.
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Quoted: There are ammo options for short barrels. But M193 is the buy it cheap and stack it cheap option. That's why I keep is as the benchmark when discussing barrel length. View Quote Considering that most of us have more than one AR, buying 'specialty' ammo for self-defense, when true AR15 self-defense rarely ever happens, is not that much of a hindrance to suggest that folks - should they buy their ammo carefully - shouldn't go with 10.5". Buy it (XM193) cheap, stack it deep, and keep the 16" to 20" upper on hand should SHTF. |
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I was in the same boat as OP a year ago.
I run both 10.5 and 11.5 barrels. I prefer 11.5 The 11.5 gives you more dwell time for the gas system. Here is a good vid... My favorite SBR Barrel lengths / setups |
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Definitely in 5.56, most likely with 55 and 62 gr. I'm not aboard the .300 Blk boat yet
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I swapped the 10.5 barrel with a Faxon Gunner 11.5.
Because for $125 why the fuck not. |
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Iirc, BCM sticks with 11.5 b/c of the advantages in dwell time, so I'd personally stick with what guys like them recommend.
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My favorite 5.56 barrel lengths are 11.5 and 14.5. I read somewhere that 11.5 gets you something like 40% more gas dwell time than 10.5, which allows for a smaller gas port and less violent cycling. No idea if that translates to better real world reliability, but I see no need to change now.
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Quoted:
I was in the same boat as OP a year ago. I run both 10.5 and 11.5 barrels. I prefer 11.5 The 11.5 gives you more dwell time for the gas system. Here is a good vid... https://www.youtube.com/watch?v=Mxwi9fAe4s8 View Quote |
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Quoted:
Are there any noticeable differences between a 10.5 in and a 11.5 in (FBI-type) AR pistol in terms of handling, performance, excess gas, wear and tear, etc.? This would not be a copy-cat build; just a general, all around AR pistol with a brace. It seems like I've read on here that there were significant ballistic advantages brought by the extra inch (ib4 that's what she said) which led the FBI to adopt the 11.5 barrel length. What are GD's thoughts? View Quote FWIW- I have a 7.5" barrel AR that runs flawlessly. While it may not provide rifle performance from M193/M855 through that short barrel, it is still more effective than MOST handgun rounds at typical handgun range. Over-penetration is definitely a concern. I have a few mags loaded with Speer Gol Dot 64gr. for HD use if needed. |
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The 11.5 advantage is dwell time. The ballistic advantage is negligible
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I guess 11.5” is more reliable, dwell time and all that. I dunno, I’ve yet to make my 10.3” malfunction for it to matter. A bit of extra frag range too I guess. An 11.5” would net me another 30m or so frag range over my 10.3”. The 10.3” gets me a good 200m or so with the right ammo anyway though, so I don’t know how much that 30m matters either.
I do have a 12.5” and it’s nice too. It’s a sliding scale of range, dwell time, and size. Where you’re most comfortable on that trade off scale is something only you can answer, and your opinion is the only one that matters for your gear. There’s not a right answer here (besides just getting every barrel length, you know, just to be safe). |
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Another vote for 11.5.
10.5 will work if you are using good ammo, but 1.5 gives you the flexibility for any ammo if needed. That magical extra inch does wonders w/ velocity and dwell time. |
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Quoted:
10.3-5 if exclusively running a can ,11.5-12.5 if going bare some or all of the time. https://www.AR15.Com/media/mediaFiles/401569/IMG_20181001_120706-01-689221.jpg View Quote |
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11.5" if you're only going to buy one length or only want to stock one or two types of ammo but realistically you can buy ammo that is designed to perform out of the shorter barrel lengths. Garand Thumb's video is a good one explaining why to go 11.5 though. That said, as already mentioned, folks always throw out the arguments against military issue stuff but it's easy enough to keep a couple of magazines of something designed for short barrels on hand.
ETA- Side note, remember you're not limited to 5.56. I dropped three deer in their tracks last season with an 11.3" 6.8SPCII. |
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Quoted:
My favorite 5.56 barrel lengths are 11.5 and 14.5. I read somewhere that 11.5 gets you something like 40% more gas dwell time than 10.5, which allows for a smaller gas port and less violent cycling. No idea if that translates to better real world reliability, but I see no need to change now. View Quote Another vote in the 11.5" column though IMHO. |
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Quoted:
Another vote for 11.5. 10.5 will work if you are using good ammo, but 1.5 gives you the flexibility for any ammo if needed. That magical extra inch does wonders w/ velocity and dwell time. View Quote I personally use MK318 in my SBR to allow for adequate expansion as well as barrier penetration. |
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Quoted:
I guess 11.5” is more reliable, dwell time and all that. I dunno, I’ve yet to make my 10.3” malfunction for it to matter. A bit of extra frag range too I guess. An 11.5” would net me another 30m or so frag range over my 10.3”. The 10.3” gets me a good 200m or so with the right ammo anyway though, so I don’t know how much that 30m matters either. I do have a 12.5” and it’s nice too. It’s a sliding scale of range, dwell time, and size. Where you’re most comfortable on that trade off scale is something only you can answer, and your opinion is the only one that matters for your gear. There’s not a right answer here (besides just getting every barrel length, you know, just to be safe). View Quote |
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Quoted: Both lengths have terrible velocities and should not be used with M193 or similar ammo for self defense that are reliant on velocity to cause expansion. I personally use MK318 in my SBR to allow for adequate expansion as well as barrier penetration. View Quote If you mean frag from M193, it has the potential to because you are still reaching the necessary velocity to have potential frag. Frag from M193 is always a toss up even when reaching the velocities required for it to happen. Oh look. Vids Why 50gr TSX Is The Ultimate 5.56mm Home Defense Load: Black Hills 5.56mm 50gr TSX Gel Test How Low Can It Go? Extreme Low Velocity .223 Federal 62gr Fusion Gel Test ***DEMONITIZED*** .223 gel test: Black Hills 77 gr TMK, (11.5" &16" bbl) .223 gel test: Hornady 55 gr soft point |
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Quoted: 11.5 doesn't have that much loss of velocity compared to 14.5 and is able to expand with with defense ammo. If you mean frag from M193, it has the potential to because you are still reaching the necessary velocity to have potential frag. Frag from M193 is always a toss up even when reaching the velocities required for it to happen. Oh look. Vids https://www.youtube.com/watch?v=S3xgcu2yNRs https://www.youtube.com/watch?v=otou1Fws4cQ https://www.youtube.com/watch?v=qXBU03vdr2Q https://www.youtube.com/watch?v=xKWojqtvHnE View Quote |
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Quoted: If memory servers, there's a reliably frag velocity and a lower might frag velocity. 10" you start at the might frag pretty much at the muzzle. View Quote 10.5 just barley hits that at the muzzle, then very quickly loses it. |
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12.5..
That's my latest, gives a little bit more velocity along with real estate. |
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11.5" has the advantage in everything except handling
I still have multiple 10.3"/10.5" |
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My wife says an inch, plus or minus, doesn’t make much difference if you know how to use it.
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Quoted:
Cartridge Information5.56mm M193 55gr Ball with BC of .243 Fragmentation threshold2700 fps (20": 130 yd / 16": 105 yd / 14.5": 90 yd)11.5" 40m10.25" 14m RangeVelocity (ft/sec)Energy (ft-lbs) 20"16"14.5"20"16"14.5" 0325931323064129711981146 25314630232958120911161068 5030372919285511261040995 752932281727561050969928 100283027202661978903865 125273226252568911841805 150263725342479849784750 175254624462393792731699 200245723622310737681652 225237222802230687635607 250229022012153640592566 275221021242078596551527 300213420512006556514491 350198819111869483446427 400185317811742419387371 450172616591623364336322 500160915461513316292280 Fuck all formatting was lost on copy paste... View Quote |
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I was thinking this and went 11.5
Because no can and I was going to put a short muzzle device on it. There's the thing about length and handling. If either way you are going with some large device or brake do the 10.5. The increase in fragmentation range going to 11.5 is actually better than you would think. There's a YouTube video out there that shows 556 is still exploding at 100m in 11 where 10 does not. |
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10.5" Advantage: PSA has near complete pistol kits for like $87
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Quoted:
I was thinking this and went 11.5 Because no can and I was going to put a short muzzle device on it. There's the thing about length and handling. If either way you are going with some large device or brake do the 10.5. The increase in fragmentation range going to 11.5 is actually better than you would think. There's a YouTube video out there that shows 556 is still exploding at 100m in 11 where 10 does not. View Quote |
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Quoted:
Are there any noticeable differences between a 10.5 in and a 11.5 in (FBI-type) AR pistol in terms of handling, performance, excess gas, wear and tear, etc.? This would not be a copy-cat build; just a general, all around AR pistol with a brace. It seems like I've read on here that there were significant ballistic advantages brought by the extra inch (ib4 that's what she said) which led the FBI to adopt the 11.5 barrel length. What are GD's thoughts? View Quote A 10.5" barrel on an AR-15 pistol with standard length pistol buffer tube will be under 26" (measurement with the muzzle attachment off) and considered to be a pistol under federal law as well as a pistol in MOST states but not ALL states. So, if you want to carry it loaded in your car or in a backpack with your CCW, be sure to know your state's (or state you are traveling through/to) definition of pistol. Some states use the federal 26" overall length definition and some use barrel length definitions so the overall length doesn't matter only the barrel length. Now to the 11.5" barrel. When you use this length with a standard pistol length buffer tube you are OVER 26" which takes the gun out of the pistol definition in MANY states so your CCW may not cover you legally if you want to carry it in your car or in a backpack, etc.. Also and VERY IMPORTANT: when your AR-15 pistol is over 26" it is no longer considered a pistol under federal law - its status is a "firearm." The advantage here is that you can legally attach a second vertical pistol grip BUT under federal law, you CANNOT conceal a "firearm" IF it has the second vertical grip attached OR IT BECOMES AN UNREGISTERED AOW. So, if you live in Virginia and have the unConstitutional (and NRA-backed) Project Exile law in effect, the local LE who arrests you for whatever is obligated to send the report to ATF so they can examine the firearms case to see if any federal laws were also broken. So if you were trespassing on private property (unknowingly) and are charged and happened to have your AR-15 pistol with 11.5" barrel with second vertical grip under your jacket, you have actually committed a federal felony in violation of the 1934 NFA. |
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Is the dwell time that much more advantagoeous with an 11.5 than a 10.5 inch barrel for reliability? IDK , but look all here with a flawless 10.5 inch upper. If your gun is just for fun than either length doesn’t matter. If you need that Fragmentation Go longer.
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Quoted:
Is the dwell time that much more advantagoeous with an 11.5 than a 10.5 inch barrel for reliability? IDK , but look all here with a flawless 10.5 inch upper. If your gun is just for fun than either length doesn’t matter. If you need that Fragmentation Go longer. View Quote |
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Quoted:
a muzzle brake on an unsuppressed 10.5" 5.56 is a great idea View Quote View All Quotes View All Quotes Quoted:
Quoted:
I was thinking this and went 11.5 Because no can and I was going to put a short muzzle device on it. There's the thing about length and handling. If either way you are going with some large device or brake do the 10.5. The increase in fragmentation range going to 11.5 is actually better than you would think. There's a YouTube video out there that shows 556 is still exploding at 100m in 11 where 10 does not. |
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Quoted: HERE IS A LEGAL DIFFERENCE WHICH MANY WHO DISCUSS AR-15 PISTOLS ON THE BOARDS DON'T REALIZE A 10.5" barrel on an AR-15 pistol with standard length pistol buffer tube will be under 26" (measurement with the muzzle attachment off) and considered to be a pistol under federal law as well as a pistol in MOST states but not ALL states. So, if you want to carry it loaded in your car or in a backpack with your CCW, be sure to know your state's (or state you are traveling through/to) definition of pistol. Some states use the federal 26" definition and some use barrel length definitions so the over length doesn't matter only the barrel length. Now to the 11.5" barrel. When you use this length with a standard pistol length buffer tube you are OVER 26" which takes the gun out of the pistol definition in MANY states so your CCW may not cover you legally if you want to carry it in your car or in a backpack, etc.. Also and VERY IMPORTANT: when your AR-15 pistol is over 26" it is no longer considered a pistol under federal law - its status is a "firearm." The advantage here is that you can legally attach a second vertical pistol grip BUT under federal law, you CANNOT conceal a "firearm" IF it has the second vertical grip attached OR IT BECOMES AN UNREGISTERED AOW. So, if you live in Virginia and have the unConstitutional (and NRA-backed) Project Exile law in effect, the local LE who arrests you for whatever is obligated to send the report to ATF so they can examine the firearms case to see if any federal laws were also broken. So if you were trespassing on private property (unknowingly) and are charged and happened to have your AR-15 pistol with 11.5" barrel with second vertical grip under your jacket, you have actually committed a federal felony in violation of the 1934 NFA. View Quote Edit: off topic but what I find weird in the GA statues is a long gun is a barrel of 18 or greater and overall length of at least 26 inches. What about 12-18in barrels? Where do they fall? |
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My 77 gr TMK hand loads don’t care if the barrel is 10.3” or 11.5”. They’ll fragment at any reasonable defensive distance.
I’ll stick with 10.3” and a can. Attached File |
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