Why all the ultra short AR barrels?

IdaD said:

also tend to agree with John Lovell's take that lots of noise in those scenarios can have some real benefits too.

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Having fired guns indoors in dim lighting and without hearing protection on, I can tell you that you're as likely to be disoriented by the experience as anyone else. This is why I value a short barrel and a can on the end of it (or chamberings that work well from short barrels), but YMMV.

IdaD said:

I get it for guys who do stuff like that for a living. I'm just a middle aged husband/dad who lives in a nice and generally safe neighborhood. I'll probably never fire a gun of any kind indoors, and if I find myself in that situation I don't think hearing loss is going to be real high on my list of worries. I also tend to agree with John Lovell's take that lots of noise in those scenarios can have some real benefits too.

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You're missing the point they're faster and easier to maneuver, if you're out of shape why hamper your movement further with a longer heavier gun.
My 91 year old father doesn't have the strength to shoot a rifle off hand worth a poo, but with the 8" 300 Blackout he's as effective as possible IMHO.

Besides they're fun

Because the commonwealth of Pennsylvania doesn't allow you to carry a loaded rifle in your vehicle & I'm aware of what's going on in the world. 12.5 is as short as I'd go for a 223/556 & only specifically because of my state regulations. Otherwise it'd be a 16 inch Carbine.

In general I like long barrel ARs. My 3-gun AR is chambered in 556 and is a 20-inch gun, my 450 Bushmaster is a 20-inch and the 30 Remington AR I am hunting with this year is a 22-inch gun.

But for suppressed ARs shooting subsonic ammo short-barrels makes a lot of sense. As other have already said 300 AAC Blackout was designed around a shorter barrel and with subsonic ammo it works even better with short barrels. Same with pistol caliber ARs much of the factory ammunition that would have been subsonic in a pistol length barrel goes super-sonic from a 16 inch barrel. So if you going to run an AR suppressed with subsonic ammo of maximum-quiet you probably want the short barrel.

With my own 16-inch 300 BO about 3/4 of the factory subsonic ammo on the market will go, at least occasionally, super sonic from my 16 inch barrel. All that same ammo stays nicely subsonic from my 9-inch.

I love my AR Pistol it goes with me every time I go out to the hunting property. It carries easy on a 2-point sling over my back hanging across my chest leaving both hands free if I need them. Goes in and out of the UTV easy and hangs from the tractor in a scabbard nicely and easy to draw.


16-inch carbine top
9-inch pistol bottom with an SDN-6 suppressor.
Both are basically the same size but the bottom one is much quieter and it shwacks Armadillos like a hammer.

Fatelvis said:

Honestly, I hadnt considered another chambering outside of 5.56. You are correct with the Blackout and AAC, but the FMJ 5.56 relies on high velocity to create an unstable projectile after impact, imparting tumbling. When you cut down the velocity, you cut down the lethality.

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You are cutting your lethality far more by choosing FMJ in a 16" than using an expanding bullet in a 10".

Bear in mind that an AR with barrel shorter than 16" is either a SBR with lots of paperwork or a "braced pistol" which the feds wish to ban or reclassify as a SBR.
Obviously a lot of people think it is worth the trouble.

Fatelvis said:

I have read and always heard that the early M-16s purposely had a slow twist of 1:12, to just barely stabilize the 55 grain bullet. The combination of high velocity, and a barely stabilized bullet was the goal. Upon impact, they would immediately start tumbling, creating massive wounds, while still using FMJ ammo.

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Nope, that is not the design basis.

Other than “because I can,” I own a handful of pistol and SBR uppers meant for hunting. A 10.5” 6.8 SPC or 458 Socom will do everything I need to kill a deer to 200yrds, and the 10.5” 6.8 or 5.56 will cleanly manage called coyotes. I don’t have to be stuck carrying an extra ~2lbs of barrel and handguard for such a menial task of short range hunting.

It’s convenient that the short and light attributes of an SBR are also advantageous for transportation and also for investigating bumps in the night, but “short, handy, and sufficiently powerful” is useful.

Meh... I have no interest in a AR pistol, and.... personally... I think they are going to be legislated into oblivion, soon, if things continue going the way they are. Having said that, I don't understand an AR barrel shorter than about 14" for general use, although I can see a shorter barrel in certain circumstances (LEO/MIL.) There is a certain 'saltiness' to a short-barreled AR... like having an SBR without the tax stamp or the trust, and they are quite tacticool, of course.

I don't judge, however... I get made fun of with my 16" barreled .308 M1a. If it works for you, and it's not illegal... it's all good.

rbernie said:

Having fired guns indoors in dim lighting and without hearing protection on, I can tell you that you're as likely to be disoriented by the experience as anyone else. This is why I value a short barrel and a can on the end of it (or chamberings that work well from short barrels), but YMMV.

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Certainly possible. I guess I was thinking more about neighbors hearing what was going on than causing disorientation, with the idea that the cavalry may be on the way if something happened to me. I've hunted for over 30 years, I'd hope I could handle some blast without getting disoriented. I've never touched off a rifle indoors, though.

mavracer said:

You're missing the point they're faster and easier to maneuver, if you're out of shape why hamper your movement further with a longer heavier gun.
My 91 year old father doesn't have the strength to shoot a rifle off hand worth a poo, but with the 8" 300 Blackout he's as effective as possible IMHO.

Besides they're fun

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I'm 42 but I'm not out of shape by any measure, and an AR with a 16" barrel is the handiest and easiest to maneuver long weapon I own. I won't argue with that last point.

Fatelvis said:

I've been scratching my head as to why every one is going in the direction of ultra-short AR pistol builds. I understand the whole pistol brace situation, but don't you think the short barrels are seriously handicapping the velocity and accuracy potential of the weapon? Just to make it a little bit shorter? To me, the trade off isn't worth it. What are your thoughts? Thanks!

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For me, it gets the weight of the suppressor in closer. A 16" barrel with a 6-8" suppressor is long and nose heavy. An SBR with a 10.5 barrel and a suppressor is very easy to shoot and not nose heavy.

Shorter barrel makes the rifle/pistol easier to move around. That could be either handling it indoors or vehicles as well as just easier storage. My 10.5" pistol build could easily fit in a backpack if I were to separate the upper and lower or get a folding adapter. My 16" rifle, not so much.

Rembrandt said:

I call it the "El Camino syndrome"......not really a car, not really a truck, but has characteristics of both.

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The potential fun for custom magazine well engraving is almost endless.

Like was said before, not all short barrel ARs are chambered in 5.56. The bearded secret squirrel types have used very short 300 Blk rifles in Afghanistan, and probably other places, with great success. It has become a good alternative to the MP5SD.

The US military Special Operations guys have been killing badguys with 10.x inch guns in 5.56 using FMJ ammo since Vietnam. My old squad leader has been running a Mk18 overseas since the mid 2000s and loves it. He has kills out past 400 meters with it as well. The Mk18 has been serving SOCOM well for a long time now and is a very well proven combat firearm. It also make running a suppressor much easier. Not only do cans help with communication during a firefight, they greatly reduce muzzle signature at night. Muzzle flashes attract incoming fire.

5.56 ball doesnt rely on speed to yaw. Spitzer shaped bullets yaw because of the lop sided shape and weight of the bullet. Fragmentation happening during yaw is mostly dependent on velocity though, unless bone or something else hard is hit. Fragmentation threshold is usually around 2500-2700 FPS depending on the bullet construction. Some rounds like the 77 SMK used in M262 will fragment much lower, down around 2000 FPS. But even if a ball round doesnt fragment it still will likely yaw and still cause significant damage through temporary stretch cavitation down to around 2000-2200 FPS. Then of course you have hollow points and soft points which offer good terminal performance at a much lower velocity than FMJ.

Ive seen a few gangland shootings done with short barrel AR and AK pistols, known as a "choppa", using cheap FMJ such as Wolf or Tula. Sub 10 inch guns at close range still create pretty effective wounds.

R.W.Dale said:

It’s just the predominant gun fad of the day. They serve no real purpose

just like a decade ago you were a gun nobody if you didn’t have a $3000 poorly running 1911. Today you are a gun nobody if you don’t have a questionably legal sbr ish AR that the BATFE may redefine into illegally again at any given time

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Seriously?

I don’t have one but for under 200 yards and suppressed, it is tough to beat a 11”ish barrel gun, 9” if it’s a 300.

Sure, the rifle was designed by Stoner for a 20” barrel, but that was to be effective out to 500 meters.

It’s plenty lethal with 11 inches of barrel out to 200 yards easy. With good ammo, further.

IdaD said:

I'm 42 but I'm not out of shape by any measure, and an AR with a 16" barrel is the handiest and easiest to maneuver long weapon I own.

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Of course if all you owned was a 34" barreled Sharps that would be the handiest and easiest to maneuver right?

I have an 8" AR, but it's chambered in 45acp so it's kind of a long barrel for caliber in that respect.

I do have a 10.5" in 5.56 though. It's handles nicely and balances well, and I can ring the 8" gong at 150 easily with the red dot or buis. I wouldn't really want to go shorter than 10" with 5.56 though.

It's a to each his own kind of thing though. People can build or shoot what they want in my opinion, only they can decide if it meets their needs, wants, cool factor, or whatever.

Zerodefect said:

10.5-14" isn't short at all.

7-8" is short.

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“short” is a relative term.

when it comes to the AR barrel, you have to determine if the barrel is too short to properly function in the gas/recoil system of the gun.

I once heard Paul B (owner of BCM) say he thought 12” was the sweet spot for length because when you went shorter, you may run into reliability issues.

But we also know 10.x has been used by SOCOM for years, so it’s reliable enough for them.

When I hear folks slam on the pistol brace and those using it to avoid the NFA SBR “rules”/tax stamp, it makes me cringe! How “Fuddly” can someone get? Instead of complaining about the brace “loophole”, how about you complain about the SBR stamp stupidity!

Charlie98 said:

I think they are going to be legislated into oblivion, soon, if things continue going the way they are. Having said that, I don't understand an AR barrel shorter than about 14" for general use, although I can see a shorter barrel in certain circumstances (LEO/MIL.)

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I don't think so, Miller and Heller both have precedent for common use. I'm not sure the SBR registry would survive a SCOTUS ruling.

Fatelvis said:

Buzz, I don’t doubt what you say at all, but I would like to see someone do a study on the actual wound characteristics between a short barreled, a medium barreled, and a 20 inch barrel, all other things being equal, to see the actual difference in lethality between them.
I love watching the videos when people shoot through bluejeans, pork ribs, and actual meat, or some other simulation of real-world performance.

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Same guns but shot at 50 yards.

I understand the appeal of them. Just not interested in the headache, either from the muzzle blast or the back-and-forth ATF legal wrangling.

mavracer said:

Of course if all you owned was a 34" barreled Sharps that would be the handiest and easiest to maneuver right?

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There's no need to be silly here. I have some lever and bolt carbine's that I would also consider very handy but still not at the level of an AR with a 16" barrel. That's a small rifle as rifles go, even with a 16" barrel. The only reason I'd personally consider a shorter barrel on an AR is to run a suppressor on it while maintaining the same overall footprint, but as I mentioned in a different post that's not something I'm interested in doing.

IdaD said:

There's no need to be silly here. I have some lever and bolt carbine's that I would also consider very handy but still not at the level of an AR with a 16" barrel. That's a small rifle as rifles go, even with a 16" barrel. The only reason I'd personally consider a shorter barrel on an AR is to run a suppressor on it while maintaining the same overall footprint, but as I mentioned in a different post that's not something I'm interested in doing.

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Whether you recognize it or not the statement is just as silly
X" is the shortest barrel I have and the gun with the X" barrel is the most maneuverable.
16" was arbitrary in 1934 and still is.