AR Pistol??

[Varminterror]

^^ Was about to drop the numbers, but @MachIVshooter beat me too it...

Way too much short barrel ignorance flying around the internet - "don't buy a Ruger Alaskan 454 because it's basically the same as a 7.5" 44mag..." or "don't buy a 7.5" AR because it's only a 22mag..." or "a .357mag in a snubby doesn't do any better than a 38spcl+P"... Typically, these assertions are plain incorrect, but they almost always neglect form factor - sure, I can hotrod my 9.5" 44mag SRH to get pretty close to my 454C SRH Alaskan - except one has ~7" more barrel and a pound of extra weight hanging out front, while the other is a handy beltgun. A 7.5" AR pistol or SBR is a heck of a lot shorter than a 22" 22WMR rifle, AND it delivers about two fold more energy... "Basically" is a pretty damned broad gap in this case...

 

[mavracer]

Wow getting called an ignorant bonehead, real high road.

At least I can do math correctly even using your inflated 2400fps ( I only got 2450 from my 10.5" barrel ) 2400x2400x55/450240 is only 703 not 930. And well below the velocity for fragmentation. At a more realistic 2200 fps you're less than 600 FPE in the ballpark with a good hot 40 S&W. I'll also point out that below 1000 FPE you start really loosing the effects from energy and momentum becomes a much bigger factor.
@ 2400 fps you have less momentum than a standard pressure 115gr 9mm and are equal to a 38 special 158 gr at 800.
My 300 blackout actually makes over 1000 FPE from an 8.5" barrel and has nearly twice the momentum.

And just for the record my brother's 454 Alaskan would do 1300fps with 300s only 50fps faster than my 4" Redhawk 44 mag and they're within a couple ounces of each other.

 

[GunnyUSMC]

I haven’t looked but it might be hard to find a 7.5” 22 magnum with a 30 round mag. Plus the last time I checked, 22 mag ammunition cost more then 5.56.
And if I wanted a little more power, I could just put my 10.5 barrel on the lower.
I also like having the versatility of rifle, carbine and pistol using the same ammo.

 

[Armored farmer]

If you want to talk .22s....and fun.?
Put a .22conversion kit on your 556 AR pistol!
I wanted to take mine squirrel hunting but..

 

[MachIVshooter]

Wow getting called an ignorant bonehead, real high road.

No, I called your statement boneheaded. Big difference

At least I can do math correctly even using your inflated 2400fps ( I only got 2450 from my 10.5" barrel ) 2400x2400x55/450240 is only 703 not 930.

In which case you should have also realized that I denoted the wrong units for both it and .22 WMR (stated FPE, accidentally selected joules in the calculator). Regardless of units, it's still almost triple the KE from a 5.56; 703 vs. 242 is a factor of 2.9. More importantly, the 5.56 stays well above the velocity threshold for rifle wounding mechanisms, while all but the fastest .22 WMR loads fired from longer barrels are under.

2,350-2,400 is not at all inflated, either. Chronographs and Google are your friends.

And well below the velocity for fragmentation. At a more realistic 2200 fps you're less than 600 FPE in the ballpark with a good hot 40 S&W. I'll also point out that below 1000 FPE you start really loosing the effects from energy and momentum becomes a much bigger factor.

There's that ignorance Varminterror was talking about. Energy can be a useful metric for comparing rounds under limited circumstances, but is a rather meaningless figure in and of itself. A handgun round producing 600 FPE with velocities in the 1,200 FPS range has a very different wounding mechanism than a rifle round seeing similar KE at well over 2,000 FPS.

Fragmentation is also not necessarily a positive attribute, especially when we don't limit ourselves to FMJ bullets. I gave figures for M193 because it's extremely common, a standard; there are plenty of 45-55 gr. expanding bullet loads which will run at significantly higher velocities from a short barrel.

 

[Zerodefect]

If we're going to split hairs about short barrels and power, then we need to take another look at shooting .300blk.

.300blk offers far more power out of a 7" barrel than a 10" 5.56. Shoot some stuff side by side with it and 5.56. Waaaaay less blast and concussion as well. Don't underestimate supersonic .300blk.

At this point, I'm pretty confident that short barrel 5.56 AR's are obsolete. Anything under 14", I'm going with .300blk. An 8" supersonic .300blk hits like an AK. Subsonic ammo is very much like a .45acp. We used to complain about .223 and 5.56 power in short barrels. Well....

 

[Sistema1927]

Anything under 14", I'm going with .300blk.

I have two 8.5" AR pistols. One in 300 BO and one in 5.56.

The 5.56 is fun at the range, but the 300 BO is the one I grab when "things go bump in the night".

 

[Zerodefect]

Absolutely. .300blk is no harder on the ears than a pistol. SBR 5.56 is blood pouring out of my ears bad, indoors.

Maybe wall overpen could be a problem more, if you miss. But if I was concerned about that, FN p90. When I move next week, I'll no longer be able to use a 12g Mossberg JM pro for home defense. Going to a country town, but the neighborhood is like the 'burbs.

 

[MachIVshooter]

.300blk offers far more power out of a 7" barrel than a 10" 5.56. Shoot some stuff side by side with it and 5.56. Waaaaay less blast and concussion as well. Don't underestimate supersonic .300blk.

At this point, I'm pretty confident that short barrel 5.56 AR's are obsolete. Anything under 14", I'm going with .300blk. An 8" supersonic .300blk hits like an AK.

Absolutely. .300blk is no harder on the ears than a pistol. SBR 5.56 is blood pouring out of my ears bad, indoors.

.300 blk has it's place, but let's be honest about what it is and isn't. First of all, .300 blk supers run about the same dB as 5.56. Unsuppressed .300 blk supers will register around 163 dB out of an 8" barrel. That's gonna ring you just as bad as the 165 of a 10" 5.56. You'd have a little less overpressure, but still instant hearing damage levels. Yes, almost certain ear bleeding if fired in a confined space.

Secondly, a .300 blk 110 gr supersonic load will run about 2,050 FPS out of an 8" tube. That's a far cry from a 123 gr @ 2,350 FPS for an AK, and in terms of energy, it's a lot closer to the 5.56 out of the short barrel than a 7.62x39 from a normal AK length tube.

That's not to say that it wouldn't be a good choice, but it ain't exactly Thor's hammer, and I don't think either you or the bad guy are gonna notice much difference when it's all said and done. 5.56 or .300 blk, He'll be leaking all over your floor, and you'll be dealing with pain and ringing in your ears for quite some time if it's unsuppressed.

There is, of course, a solution. Ear pro is one. I go for the more expensive but also more practical and dynamic solution.

 

[harrygunner]

I kept trying to avoid reading this thread, but failed. So, I went looking at AR pistols. Thought it would be good in the car when I'm traveling.

Handled a CZ 805 Bren S1 AR Pistol. It has an 11" barrel, so 5.56 ammo loses about 300 ft/s compared to carbine ARs.

No buffer tube sticking out the back, never did like that for a "pistol".

So, I'm hooked. Will be my Christmas gift to myself.

 

[Armored farmer]

Another nonbeliever joins our ranks.



My ar pistol is my favorite ar.

 

[Panzerschwein]

Very cool, I'd imagine an AR pistol would be a nice little car gun.

Wonder what armor penetration is like from an AR pistol and green tips?

Wonder if it's better than 5.7x28mm with APs?

 

[harrygunner]

The CZ Bren AR pistol isn't cheap, but worth consideration. The upper is reconfigured to hold the 11" barrel while keeping the overall length of the gun under two feet. I can place it in a daypack.

I read CZ will be providing stocks for those wanting to convert them to SBRs. I personally won't be making the conversion. I live in a state where I can have loaded rifles in my car, but not all nearby states do. With a pistol, no problem keeping a 30 round mag inserted. But for those interested, that option should soon be available.

 

[strambo]

I just ordered an 8.5" .300 BLK upper from PSA. Was a back-burner project, but the weekend deal price of $260 with BCG, CH, and 7" M-Lok rail was too hard to resist. It was the milspec quality BCG and melonite barrel as well, not even the lower end "Freedom" line. I have a stripped lower waiting to fulfill its destiny.

Probably build out the lower with the KAK shockwave blade brace. It will be a nice "get home" gun that I can carry with my CCW and be under $500 including what I paid for the stripped lower.

Edit: It is still in stock at that price. http://palmettostatearmory.com/psa-...m-lok-railed-upper-with-bcg-ch-516446485.html

They have a stainless barrel model less BCG for $199 and one with a 9" rail, KAK muzzle device and MBUIS for $299

 

[Varminterror]

Wonder if it's better than 5.7x28mm with APs?

You'll get more out of a 5.56 than a 5.7. Same bore, but the 5.56 has twice the case capacity, and operates at a higher max pressure. You'll get a lot more blast of excess plasma out of a 5.56 too, naturally. Quite similar to a 221 Fireball - the 5.7 was made for a shorter barrel than the 5.56, so it has powder capacity more commensurate with its bore volume. Alternatively, since we're now kicking the 300blk can down the road, the 300 has similar case capacity and max pressure as 5.56, but a considerably larger bore cross section - again, making it more efficient for LENGTH.

 

[MistWolf]

Gunny, if I'd gotten to this thread sooner, that's the very same arm brace I was going to suggest you try. It's what I've been using since the Galil Ace version was introduced. I've used it to shoot hundreds of rounds and except for the LOP being a bit short, I have always been satisfied with it.