Rifle or pistol cartridge sbr?

[B.A.]

I'd like to build an sbr some day but my question is what's better rifle or pistol calibers. I'll start with the fact I'm not a fan of .556 so let's not even touch this, you won't change my mind so don't bother. Now that that's out of the way, would it be better to have a sbr in 7.62x39 or in 9mm or another pistol caliber.

My concern is that rifle cartridges are generally designed with the idea of being fired out of a rifle barrel typically most are between 16 and 24 inches when it comes to millitary style rifles. Where as pistol rounds are intended to be fired from shorter barrels most full size pistol barrels are around 5 inches. So what's better for a barrel length of 10 inches which is right between?

I was contemplating doing a m92 krinkov build or a AR47 sbr but I'm curious to see if a 9mm or other pistol caliber AR would preform better. Plus a suppressor down the line would be cool as well and it's way easier to get hands on a pistol suppressor than 7.62 suppressor.

Any intelligent thoughts will be appreciated.

[Nate7667]

Well since you stated the 556 is out, what about the 300 Blackout?
Same parts and pieces as any other AR except the barrel. mags are cheap and plentiful. No special mags or mag blocks needed.
110-130gr 30cal ammo out of 8-10" barrel is pretty sweet.
200-240gr 30cal ammo out of 8-10" barrel is pretty quiet.

Most pistol caliber (9mm) suppressors on the market today can handle sub sonic 300Blk.
So you have a versatile can, shoot 9mm and 300Blk.

Pistol caliber (AR platform) needs either a proprietary mag well or drop in mag block.
You are still limited to pistol ballistics.
Not saying a 147gr 9mm would not ruin your day.

The AR47 is an interesting creature. works ok, mags are tough to find and tough to find cheap, different bolt face.

Stepping away from the AR platform, the good old AK.
Well, its an AK. What cant it do?
Pick your flavor and get it shortened.

Im not sure what you mean about pistol suppressors being easier to get.

[CPratt]

If you are going to suppress it and you want it to really be quiet I would go with a pistol caliber.

I have a AK SBr with a 12-1/2" barrel and it's pretty loud with my YHM can on it.

As for ballistics I'm not sure which way you would be better to go.

[robrat]

Go with a 22LR - Cheap to shoot, fun, and very quiet suppressed. Past that, pistol cal.

I went the AR route - started with a 6-1/2" 22LR dedicated upper, since I had a 22LR suppressor already. Just built a 5.56 10-1/2" upper, and have it set up with a QD mount for a 7.62 suppressor, originally purchased for a 300/221 upper. Planning on having the 300/221 barrel shortened, now that I have the SBR stamp. Also planning on a 45ACP suppressor purchase for my 1911...that will give me options of building a 45ACP upper or 9mm upper.

2 pins give you a lot of caliber options for 1 stamp.

[fastfive0]

The only caliber designed specifically to outperform all the others from an sbr....300blackout....go 8" and enjoy a powerful/accurate and almost movie quiet when suppressed with subs! It's a no brainer!

[JayBell]

I myself have an AR SBR I regged back in 98... it have a 11.5" 5.56 upper, a 8" 22lr upper, 2 9mm uppers(11.5 and 8")... and I've sold my x39 and 45acp uppers in the past... the 9mm uppers are decent, both suppressed and not, and the 5.56 just gives me something a bit more violent to mess with too... but overall, since the AR platform is the "swiss army knife of guns" do one of those.

[B.A.]

Yeah but isn't .300 expensive? I want something that's not gonna make me have to get a second job to shoot.

[EvoRich]

7.62x39 is typically not very reliable in the AR receiver, due to the curve need for the magazines. The mag has to straighten out as it enters the receiver and makes the feeding angle awkward.

I would just buy a Draco in 7.62x39 if that's the caliber you want, then SBR that. Or an AR in 300 Blackout, since it uses the same case size, and taper, the ONLY thing different needed to run a 300 in a 5.56 gun is a barrel.

As for pistol calibers, I'd only want a .357mag or .44mag lever gun. Pistol calibers are for pistols.

[orionz06]

There are no issues with rifle cartidges being "designed for 16"-24" barrels", just lower velocities. Some rounds are quite effective out of the short barrel still.

I am not a fan of 300BLK for lots of reasons but you might end up liking that flavor of Kool-Aid and its high ammo prices and low availability. Especially if you are just shooting paper with little expectations of accuracy and range. It suppresses well and is sold by a suppressor company, figure the rest out. When I wanted a case of ammo in less than 3 weeks there was no place to get it...

Pistol rounds are useless in longer barrels for anything other than steel matches and plinking. That may or may not matter depending on your use of the gun.

Perhaps a short AK might be a better option for ya, short AR's are a dime a dozen. When the time comes for a short AR you can then see what happened to 300BLK, if it is even around.

[PA1936MN]

Go custom and use the wonderful 7.62x25mm (Tokarev).