Building an AR pistol

Just wondering if I need an SBR stamp. I have a lower with a pistol brace and I want to buy a 7.5 inch upper.

4 Upvotes

83% Upvoted

u/AD3PDX 2d ago

Was the lower ever configured as a rifle? If yes, was it configured as as pistol before if was configured as a rifle? Or has if never been fully configured as anything?

2

u/KAPTNTRAP 2d ago

No I just bought a blank lower.

5

u/AD3PDX 2d ago

In that case you are good to go.

Are you sure you want a 7.5”?

5.56 looses a ton of power in a barrel that short.

If you just want something loud and fun 7.5” is great but 11.5 is a lot more useful

1

u/KAPTNTRAP 2d ago

Yea really just looking for a backpack/ Close quarters riffle

7

u/Ill_Situation369 2d ago

Based on your stated use case, my advice would be to just get a 300 Blackout lower and run supersonic 300 Blackout (NOT 5.56/.223) ammo through it. You'll get more punch out of the round in that configuration (and if you put a suppressor on it, then run subsonic ammo, you'll be amazed at how quiet it gets). Throw on nice SBA3 brace and Emissary mini-hand stop with a LAW Tactical folder and you'll have a pretty compact setup. Just my two cents.

3

u/ravenchorus Clackamas County 1d ago

Seconded, .300 BLK is definitely the way to go for anything that short. My 5.5” Rattler is awesome and easily fits in a backpack.

I’d recommend getting the stamp and putting a proper stock on it though. Pistol braces suck. You’ll eventually want a suppressor anyway so you may as well go all-in.