Pistol AR-15 - I'd like some thoughts from y'all

[Axeman]

I recently read a surprisingly well written article about the usefulness of AR pistols (can't remember which website).
In the past I hadn't been a fan of the idea, especially since you couldn't set the thing to your shoulder, and I thought the ballistics of a .223 from a barrel shorter than 16" would be stupid.

But this article changed my mind. The writer talked about the merits of having a rifle-caliber firearm in a smaller package that could be concealed legally in a backpack, and also brought the cogent point that in many states it is illegal to travel with a loaded rifle. A loaded pistol, however, falls under the reciprocity of our CCW permits.

I tell you all of that to get to my question: What barrel length do you think is the shortest that will still give me decent terminal ballistics?

I'd like to go as short as possible. I looked at 10" barrels and decided with the 8" upper attached it would never fit into a backpack, especially with any muzzle device attached. If I ever decided to put a suppressor on it, it would take too long to assemble if I needed it in a hurry.
So I'm trying to find that sweet spot between concealabilty and velocity.
Also appreciate any thoughts on lightweight options, muzzle devices, sights, buffer tube covers, etc.

 

[1776]

There are buffer tube kits that abbreviate the length needed by using a dual spring set-up. One of those, combined with a 7.5-8" upper and small muzzle device would give you a weapon that could fit in a backpack.

I have a 10.3" barrelled AR with an A2 FH and an MVB ARC stock that's just over 23". It doesn't fit in a lot of backpacks, but there are a fair number of decent options.

 

[AtlMedic]

I have thought about the same thing and have thought of doing it in .300blk since that round is supposed to do better out of a short barrel.

 

[Leshaire]

Im interested in the article if you can find it?

Im in the market again to slowly build something since the SET lowers are about to drop! Looking for something small and to be a pistol, maybe 300 but not sure yet.

 

[cbh13]

I've built a few and here are my thoughts. I really like them for the small package and cool factor, though if your wanting truly backpack small I'd suggest going with one that can use a folding pistol brace like this.

now all that being said I've honestly been debating dropping out of the pistols game. In .223/5.56 it just doesn't make any sense to me with the diminished performance and accuracy you get out of a shorter barrel (in my mind 5.56 is a medium range round and neutering it gets rid of that ability) plus it is fucking loud as all get out and that would probably be my biggest gripe about sbr 5.56. Now when you look at something like 300 blackout it makes a whole lot more sense (only pistol I own now is 300blk) as you don't loose much performance or accuracy out of the short barrel, and while still loud its much more friendly to the ears than 5.56 in a short barrel.

now all of that being said the main reason I've debated getting out of them is when I honestly stopped and thought about any of my what if scenarios, and to me the only real area where a pistol/sbr has an advantage over a full length rifle would be indoors where the maneuverability becomes key. Only issue to this is when transitioning to inside your making the noise issue even worse, to where the only round I wouldn't mind firing out of a pistol inside would be sub sonic 300blk which is nothing more than .45 in a long case. Because of this I've decided to look into moving away from rifles with pistol length barrels and move more into pistol caliber carbines such as the scorpion.

Now then if all your wanting is a rifle cartiage you can fit into a backpack then I'd take a hard look at the keltec su16b, I've seen them in backpacks before.

 

[scand]

This was a KelTec I did for a customer. Midwest Ind rail and cheap BSA red dot (it was a 22). It was nifty...the 223 versions are identical and can be had for cheap as well

 

[Axeman]

Wow - some good opinions out there! Let me answer in the order they came in:

@1776 I think that's the direction I'm already headed, but I'm considering going to the 7.5" barrel for shorter length. The dual spring buffer tube kits are expensive, but a good idea. I'll add that to my idea bulletin board.

@AtlMedic Since .300blk is basically the same ballistics as the 7.62X39 and I have a couple SKS rifles that I love, I'd go with that round first - that way I don't have to get into YET ANOTHER cartridge, and an expensive one at that. Also I've read enough about people (morons) accidentally dropping a .300blk round into an AR mag and destroying their rifle. So I guess I'm saying I'm just not sold on the real usefulness of the .300blk cartridge when there are others that will do the same job.

@Leshaire Might have been on TTAG, or CDNN's website, or any of a hundred others I get emails from. It was about 60-90 days ago, and I just can't recall. Sorry!

@cbh13 The first pic you posted seems like EXACTLY what I had in mind. Folding buffer tube, short barrel, just unfold that sucker in a hurry and go to work. Basically a better option than my G17 if the excrement truly meets the rotating wind generating device. I'm thinking that without the Sig Arm Brace it would be lighter, and now that ATF is "ok" with the occasional shouldering of the pistol AR, just drop some paracord around that buffer tube? I've never shot one in that config, so I don't know what the recoil would be like. Maybe I should try removing one of the stocks from a full-length rifle and see how uncomfortable the recoil is without the stock?
You said "In .223/5.56 it just doesn't make any sense to me with the diminished performance and accuracy you get out of a shorter barrel (in my mind 5.56 is a medium range round and neutering it gets rid of that ability) plus it is fucking loud as all get out and that would probably be my biggest gripe about sbr 5.56". Here's why I'm still headed that way - the terminal ballistics of ANY centerfire rifle caliber round will still be better than pistol calibers. If I'm wrong about that, please show me. (maybe .44 Mag is the exception vs .223 without looking it up, but I'm not considering revolver rounds for this purpose)
So compared to my other pistol-sized options, the .223/5.56 will still offer better performance. I'm not going to be expecting 1 MOA groups at 400 yards or anything stupid like that. As for your maneuverability issue, this is another win, especially if I add a small can for indoor use or even toss it in the backpack in the car to get around the noise problem.
Regarding the Kel-Tec SU-16, this gets me back into a RIFLE, which has issues when carried LOADED across state lines. So I like the SU-16, but not for this purpose.

@scand That SU-16 looks pretty cool - but can you really control that thing, or is it made for drive-bys? While I'm not looking for 400 yard 1MOA groups (like I told cbh13) I'd like the option of being able to hit something at 100 yards if I really needed to.

Thanks to you all for the replies, and keep them coming!
If you really think I'm wrong about something tell me! I'm not gonna go all crazy on you.

 

[Crusader1969]

While I've yet to build an AR pistol the lower I have sitting at home will turn into one. I like the idea of having something in my truck while traveling or out checking farms that is heavier than my carry pistol. I like the AR pistols in a caliber other than .223/5.56. .300 and a few others work well in the shorter barrels and allow you to carry more firepower. That's my thoughts on it.

 

[cbh13]

@cbh13 The first pic you posted seems like EXACTLY what I had in mind. Folding buffer tube, short barrel, just unfold that sucker in a hurry and go to work. Basically a better option than my G17 if the excrement truly meets the rotating wind generating device. I'm thinking that without the Sig Arm Brace it would be lighter, and now that ATF is "ok" with the occasional shouldering of the pistol AR, just drop some paracord around that buffer tube? I've never shot one in that config, so I don't know what the recoil would be like. Maybe I should try removing one of the stocks from a full-length rifle and see how uncomfortable the recoil is without the stock?
You said "In .223/5.56 it just doesn't make any sense to me with the diminished performance and accuracy you get out of a shorter barrel (in my mind 5.56 is a medium range round and neutering it gets rid of that ability) plus it is fucking loud as all get out and that would probably be my biggest gripe about sbr 5.56". Here's why I'm still headed that way - the terminal ballistics of ANY centerfire rifle caliber round will still be better than pistol calibers. If I'm wrong about that, please show me. (maybe .44 Mag is the exception vs .223 without looking it up, but I'm not considering revolver rounds for this purpose)
So compared to my other pistol-sized options, the .223/5.56 will still offer better performance. I'm not going to be expecting 1 MOA groups at 400 yards or anything stupid like that. As for your maneuverability issue, this is another win, especially if I add a small can for indoor use or even toss it in the backpack in the car to get around the noise problem.
Regarding the Kel-Tec SU-16, this gets me back into a RIFLE, which has issues when carried LOADED across state lines. So I like the SU-16, but not for this purpose.



Thanks to you all for the replies, and keep them coming!
If you really think I'm wrong about something tell me! I'm not gonna go all crazy on you.

oh you in no way can be wrong about this lol its all about what YOU want.

you are correct terminal ballistics out of those rounds will still be better than any pistol round i just personally couldnt stand the blast off of them but if you have a small can to go with it then that would take care of any of those issues. I've also shot a pistol with just the buffer tube and it wasnt bad at all, with some paracord i dont think you'd have any issues. When it comes to caliber they all have some pro's and cons, 5.56 biggest con your not going to get all of your performance, pro its still light shooting in a pistol and all the parts are baisc: 7.62x39 Pro has better performance out of a shorter barrel, cons it also has the loudest blast and im just not a fan of proprietary magazines and bolts so if going with this round i would think a pisol ak would be a better choice: 300 blk Pro has the best performance out of a short barrel and uses regular mags and bolt, cons would deff be the price of ammo but currently the price isnt bad at all and you can get it for around .30-.40 a round. then theres all the other fun stuff too look at like .458 and all the 6.5s but i have zero experience with any of them in pistols, .458 seems fun though.

 

[EugenFJR]

I ditched the pistol idea, when the ATF reversed its self on shouldering the SIG brace, now that's it's OK to shoulder a Shockwave. I'll build another pistol. I'm going to go with something like a 10.5 barrel. I know it's loud, but I don't want to lose anymore performance from the 5.56 round, and I think a 10.5 will run better with less issues. Also, remember you can store it with the upper and lower detached, all it takes is a few seconds to put it together. And 3 or 4, 30 round mags is a lot of fire power.

 

[Axeman]

oh you in no way can be wrong about this lol its all about what YOU want.

you are correct terminal ballistics out of those rounds will still be better than any pistol round i just personally couldnt stand the blast off of them but if you have a small can to go with it then that would take care of any of those issues. I've also shot a pistol with just the buffer tube and it wasnt bad at all, with some paracord i dont think you'd have any issues. When it comes to caliber they all have some pro's and cons, 5.56 biggest con your not going to get all of your performance, pro its still light shooting in a pistol and all the parts are baisc: 7.62x39 Pro has better performance out of a shorter barrel, cons it also has the loudest blast and im just not a fan of proprietary magazines and bolts so if going with this round i would think a pisol ak would be a better choice: 300 blk Pro has the best performance out of a short barrel and uses regular mags and bolt, cons would deff be the price of ammo but currently the price isnt bad at all and you can get it for around .30-.40 a round. then theres all the other fun stuff too look at like .458 and all the 6.5s but i have zero experience with any of them in pistols, .458 seems fun though.

I agree wholeheartedly with all of the Pros and Cons you listed for each of those calibers - which is why I have the SKS for 7.62x39, and not an AR-15 in that caliber.
I did find a list of velocities for .223 at Ballistics by the Inch (http://www.ballisticsbytheinch.com/223rifle.html) and they show 55gr Rem UMC leaving an 8" barrel at 2380fps, with the same load doing 2616fps from a 10" barrel. With pistol cartridges/velocities, I know a difference of 236fps can mean the hollowpoint will not open and the bullet will overpenetrate and fail to perform. But at Rifle velocities I'm not so sure it makes that much difference to lose 200+fps. They didn't have any data for .300blk or 7.62x39.
I'd think the recoil of the heavier bullet in a .300blk might be a bit more to handle in pistol format.
Thanks for the info about the buffer tube. That's the cheapest and lightest way to go, plus - who doesn't want extra paracord hanging around?

 

[Axeman]

I ditched the pistol idea, when the ATF reversed its self on shouldering the SIG brace, now that's it's OK to shoulder a Shockwave. I'll build another pistol. I'm going to go with something like a 10.5 barrel. I know it's loud, but I don't want to lose anymore performance from the 5.56 round, and I think a 10.5 will run better with less issues. Also, remember you can store it with the upper and lower detached, all it takes is a few seconds to put it together. And 3 or 4, 30 round mags is a lot of fire power.

AHA! There are problems with reliability with the shorter barrels? That's certainly something to consider! What kind of problems? Solutions for those issues?

I know I can disassemble the upper and lower (I've built several AR-15s and an AR-10), but for a quick reaction tool I'd rather it be as ready as I can get it.
With a folding stock (expensive) I'd just have to keep a round in the chamber, flick the stock open and lock it, then off-safety and make it hum.
Or I could keep the chamber empty and rack a round into it, adding a step ( I just always feel weird about a chambered rifle, but this hypocrite ALWAYS carries a chambered pistol, go figure).
I'd think it would take longer to drop the upper in, line it up, throw the pins, then rack in a round, flip the safety and put it to work. But that's just me - I'm NOT Army- trained.

By the way, Thank You for your Service!

 

[karlvv]

I have a 7.5. They are angry and obnoxious. You can shoulder them now but that angyness at your face is hard to deal with. If you go 7.5...put a muzzle device on it.

 

[Axeman]

I have a 7.5. They are angry and obnoxious. You can shoulder them now but that angyness at your face is hard to deal with. If you go 7.5...put a muzzle device on it.

DO you have anything on the muzzle right now? Even an A2 birdcage? That'd be the LEAST I'd put on it, maybe one of the muzzle blast redirects they're selling everywhere...

 

[karlvv]

DO you have anything on the muzzle right now? Even an A2 birdcage? That'd be the LEAST I'd put on it, maybe one of the muzzle blast redirects they're selling everywhere...

I have an a2 but it still shits fire 18 inches.

 

[Red Dawn]

Some good points made already. @NolansMindset built a 10.5 with the Surefire device on it. There's a video on here testing the Echo trigger install I'm sure he could be of some help here as well.

 

[fyroc]

5.56 loses most of it's performance with barrels under 10 inches. Saying that, I wouldnt go anything shorter than 10.3.. If you want something in your backpack you can always take it apart. You're already wasting time getting out of the backpack so having to put it together, (2 pins, mag, charge) will not add much more time in comparison.

I use my Mk18 for when I go out of town and I break it apart to conceal in a backpack.. I dont have an issue with putting it together.
As for the folder doohickey thingy... I never really trusted it personally.

Also, maybe an AK pistol with no stock would be better for quick deployments from a backpack?

 

[Axeman]

5.56 loses most of it's performance with barrels under 10 inches. Saying that, I wouldnt go anything shorter than 10.3.. If you want something in your backpack you can always take it apart. You're already wasting time getting out of the backpack so having to put it together, (2 pins, mag, charge) will not add much more time in comparison.

I use my Mk18 for when I go out of town and I break it apart to conceal in a backpack.. I dont have an issue with putting it together.
As for the folder doohickey thingy... I never really trusted it personally.

Also, maybe an AK pistol with no stock would be better for quick deployments from a backpack?

Is 250fps a really serious drop in velocity for a 55gr .223? I don't think it really reduces the energy much. Do you have any data to support this?
I had to look up what a Mk18 is, so I guess you're running it as a SBR.
Definitely considering your point about the folding doohickey. Perhaps I should go a different route and get a Dolos quick release barrel system...I understand they're cheaper than the DRD (who uses a proprietary upper, which is crazy expensive) and can work with YHM handguards and a few others, which DRD can't, and only has a 12.5" handguard. All of this is a shame since DRD is only a few miles from me and I'd prefer to help local industry. But if there's a better product in Tennessee...

Thoughts on Dolos? Seen one in use?

As for the AK pistol - I'm just not (YET) a fan of AKs. And the pistol version seems even less accurate since there's no way you can shoulder it even if there aren't any Gov't agents around. I like my SKS rifles - simple as a Sesame Street coloring book. But also not a work of art.

 

[Axeman]

I have an a2 but it still shits fire 18 inches.

Damn. Time to get a better muzzle device.

 

[karlvv]

Damn. Time to get a better muzzle device.

Fo sho. It scares me every time I pull the trigger. I'm pretty sure it pisses the neighbors off too.