I've got a can in jail and want to have a 308 SBR that isn't a SBR; don't want to wait months and months more for approval. So, I'm contemplating something like a 10" barrel (plus the suppressor) on a pistol stock with a tailhook or thordsen saddle.
Dumb or brilliant idea? I am trying to limit my calibers to 5.56 and 308 only, no interest in 300blk unless that's my only option.

It can be done, make sure your suppressor is rated for a barrel that short.

Why neuter all the advantages of the .308 cartridge?  Sorry, but I vote dumb!

10.5

runs like a champ. should still be able to hit a 18" plate at 900 yards.

that's at least what some have done

Both of mine are flawless after a little tuning

I like my .300 blk pistols,   I don't think I would like a .308 pistol through, my old wrists are not quite a strong as they used to be.

That's gonna be one loud motherfucker, take it to an indoor range :P

Got a can for it inbound. Trying to keep it as short as possible with the can.

Am enjoying my 12.5 inch barreled 308. Had a 10.5 but had KAK Industries (where I purchased the complete upper) swap it out for a 12.5 inch barrel. Go for it. I shoot hornady 150 gr fmj since I can buy these cheap bullets in bulk. Same with 168 A-Max I buy in bulk. Cheaper. Waiting on suppressor to be removed from NFA grip so I don't have to pay the $200 dollar extortion fee. It's in pistol form now.

Did you build it yourself? Any recommendations for parts including complete uppers, lowers or pistol? thanks

I purchased the complete upper from KAK Industries on a Black Friday sale. The lower is an Aero. KAK super tube. Had a sig brace but it add allot of weight. Shockwave works better but the hard plastic can sting a bit on the shoulder. When KAK had a sale on the 12.5 inch barrel, I jumped on it. Tighten my groups up.

While I don't have a AR10 pistol yet. . . my 8.5" PTR91 PDW sure as heck scares the shit out of people at the range. They asked me kindly to give other shooters a warning before doing another 50 rd mag dump with it.

I have a few AR pistols. Maybe an AR10 pistol is next.

Even with a flash suppressor/brake, folks still get up and leave when I shoot mine. Still loud. Love it! Go ahead and build one. You will love the power.

IMO 12.5 inches is best inches for .308, not sure I'd drop down to 10.5 but plenty have done it with great success

Although the 10.5 inch barrel I has was ok @100 yards, was worried about longer range. Nice and compact. But after going 12.5, my groups are better and feel confident to shoot 300+ effectively. Gained about 150 fps with same load too.

This pretty much articulates the problem - indirectly. The .308 just isn't efficient in a 10.5" to 14" barrel.

Back when metallic handgun silhouette was popular cartridges larger than the .30-30 were pretty much avoided due to the excessive noise, muzzle blast and limited efficiency and poor accuracy.   I shot another competitors Wichita Silhouette pistol in .308 once. It was a lot like shooting a hand sized 16"/50 naval rifle.  It had the classic battleship like mushroom cloud muzzle blast.

Cartridges like the .309 JDJ were developed to provide much better efficiency for shooters who wanted .308 rifle performance in a shorter barrel, and in fact the .300/.223 based cartridges were all motivated by this same need in metallic handgun silhouette shooting.

In other words, the poor efficiency of the .308 (and even .30-30) in short (10" to 14") barrels, is why we now have the .300 Whisper, .300 AAC Blackout, etc.    

I vote "dumb idea" on that basis.  



Those people also probably think you're a dick.  I don't know you, but you might want to at least consider the possibility that they might not be wrong.

Personally I classify those same obnoxious and inconsiderate shooters in the same category as Harley owners who install massively loud pipes and then put ear plugs in to protect their hearing - ignoring the public disturbance they are creating.   I suspect it's part psychological compensation for something, and perhaps just part "screw you, it's all about me".  

I vote "dumb idea" on that basis as well.

Well, when I am already at my lane and they sit next to me, already know how loud it is, that"s on them. But I don't sit next to someone already at a lane and start cracking them off. Everyone has there own reason for a shot barrel AR. I like the energy at closer range and able to use in CQ much better than a full size AR. Am still accurate well above 300 yards. 300 BO drops around that range. If you don't like a short barrel 308, don't build one. There is a guy on these forums who built a 8 inch 338 federal. Now that"s one load SOB. But, his choice!

Since when?  that would have to be the user not the gun

kak 308

That's where I purchased my 308 upper. It's called the McClane. But I changed the barrel out to a 12.5 inch barrel. I prefer to shoot heavier bullets. I shoot 168 gr A-Max and 150 gr fmj. Love it. Energy @500 yards is 959 ft lbs. Energy @100 yards is 1821 ft lbs. Don't think I'll have issues knocking something down!

I bought a DPMS 16" barrel and had it cut by Rainier Arms before 12.5" was readily available. With barrels as cheap as they are these days, just find a cheap carbine length gas system 16" and add $60 for the cut and thread. If you can find a factory 12.5" barrel for less, then buy that instead.  

It's loud without a suppressor but it's also a .308 pistol that shares mags with my other 308 rifles. I honestly don't think it's any louder then my 10.5" 7.62x39 SBR

I currently have a complete AR308 pistol and a 2nd one in the "working on it" stage.


ETA: Hell I may buy one of these myself

https://www.classicfirearms.com/ar10-barrel-308-parkerized-2491

That's the nice thing about owning 308 in both bolt action and semi auto. Can share between the two rifles.

what suppressor are you waiting on?

Im in the same boat and want to know what a good combo for a muzzle brake and buffer combo to get the recoil down as much as possible on a 10.5"

Ive looked at those piston/hydraulic style buffers and am wondering if they really work well...anyone know?

I just finished my 308 pistol, 12.5" Ballistic Advantage barrel with Superlative Arms bleeds off gas block, extra power spring and SLR rifleworks comp. Recoil is more than manageable, less than my 450BM, 458Socom or 50B. Follow-up shots are a little off so I have hydraulic buffer and spring combo on the way, planning to play around some more.

I had a flash can on the 10.5 and the 12.5 inch barrel. Got a deal on the war comp so just waiting to see if they pass the law removing suppressors from the NFA grips. No way will I pay the $200 extortion fee ! Helped with recoil a bit too.

Where's the pic?

I will try and get some tonight after work or tomorrow. I thought I had some prior to switching the muzzle device and before the forward controls but cant find them on my phone.

my 308 pistol

That sir is BAD ASS! How do you like the brace? I started with a sig brace, then went to a shockwave. The hard plastic of the shockwave kind of sucks.

haven't shot it much but my other 308 has a shockwave. the hard plastic does suck. but I have toned the recoil down with upgrades so its not to bad.


Adjustable gas block
Kak 5.5 buffer
JP spring

you want the minimum amount of gas to cycle

I need to get an adjustable gas block. I use 8208 XBR with 168 A-Max and 150 FMJ bullets. Took me awhile to get both to have the same POI @100 yards adjusting the powder. Would be nice to remove these short barrel "pistols" from the NFA. Not much different than a desert eagle in 44 mag or similar.

Maybe you should stick to 22LR. Maybe to much rifle for U!