This PSA pistol lower for starting a .300 BlackOut build? GTG or no?

Shouldn't be a problem...

Now, correct me if I'm wrong, since I'm still relatively new to the AR side of every thing. But, if I have an AR pistol with my short upper, I'm still permitted to have my 16 inch rifle right beside of it as long as that short upper doesn't leave the pistol lower, right? Or is there that 'constructive intent' issue there?

Relax, the Feds will never come looking for you for that sort of thing. Only used to trump up charges.

As long as both uppers have a legal purpose or configuration they can  even be separated. You just can't have the rifle lower with rifle upper and the pistol upper without the pistol lower in your possession.

Doesn't matter if it leaves the upper or not.  Would have to be in a parts grouping that could ONLY be used to make an NFA firearm.

- OS

Thanks Rogue, that's what I was looking for. Since the ATF is in my back yard, I suppose I could contact them for clarification and carry some paperwork in my range bag. I'd just hate to build one and then not be able to take it out on the same range trip.

Another clarification I'd like is if you build an AR pistol, you can SBR it later, correct? When I was reading about both types of builds that's how I understood some people do it. They would build their AR pistol and then submit paperwork for the SBR. Is that conclusion I've made correct?

Yes.  You can file a form 1 to make a sbr out of your pistol OR rifle.

Perfect, that's what I thought. Some times it can be a pain to understand some people's version of English on the internet.


ETA: Will that particular lower's buffer tube work with the SIGTAC? Looks kinda wonky.

I have that buffer tube and a SigTac. I will be assembling them later today. My PSA lower is on the UPS truck to my FFL. I can post pics later on today if requested. I did a partial dry fit and it seems like it will do without any issue but final assembly will surely tell.

That would be great man, much appreciated. I may just pull the trigger on the lower today.

Jeeze, this really is a sickness, I just put my first AR together yesterday. May have to get a few more jobs.

Here ya go. Tight fit but it works and with this thing tight is good. I haven't pushed it up all the way yet. I have about another inch or so to go. Want to test fire it first.









Build is a 9mm AR with 10.5 barrel. PSA Upper and Lower. To the range I go. May the fun begin!!!

Added on more pic

Looks good! So, how far does it go up on the buffer tube? Can you adjust it on there to make it easier to shoulder (if shouldering) if you like a longer length of pull?

The SigTac is not designed to be moved or slid on the buffer tube like a typical AR stock. It is a snug fit. You can slide the SB15 all the way up against the buffer tube plate if you'd like. With it about an inch off it feels very comfortable when shouldering.

I've built 4 systems, including a recent 300bo pistol from PSA parts and they've been GTG with one minor exception.  And that's with that particular configuration.  The sling plate was too tall to allow the charging handled to ride over.  I had to grind about a few thou off the top to flatten it out a bit.

FWIW their so called blemished uppers and lowers?  I bought a blem upper for this build and all it meant was the anodizing was more a very dark grey than a black.  The funny thing was, a quick swipe with 2 cents worth of frog lube and it matched my lower exactly saving me $20 on this build.

Note there's no crown nut so replacing the sling plate might possibly be a little, not a lot but a little, difficult because the thickness of the plate and the threading on the pistol tube is what stops it at the right position it to hold down the buffer retaining pin.  The tube is also what holds the plate against the lower, there is no crown nut to adjust the tube in and out or hold the sling plate in position.

And with no crown nut you may want to use some blue loctite on the tube threads or a strap wrench to torque it down a little more than hand tight.  

The sig brace fits.  It is very tight though which isn't a bad thing.  As in tight enough it's put the muzzle on the floor and really lean on the brace to with a lot of weight to get it moving after the first 3 inches.  Tight enough you shouldn't have to use an spacer if you don't want the arm brace all the way on.  There's very little chance it's gong to move on you, at least at first, the rubber might get warm during summers and soften up.

Thanks for the info guys. Top, can you post yours? Also, I could have sworn I saw 300 BO uppers a few weeks ago that weren't too bad price-wise, but all I found yesterday were 900+.