Sorry if this is a dumb question but I want to make sure I'm legal. I have an 8.5" 300Blk complete upper. I am looking to buy a complete lower. Is there a certain type of lower I need to buy to make it legal or can I buy any lower. Also, does the lower have to have a brace on it vs a stock since the barrel length is 8.5"?

Thanks in advance?

Barrel length under 16" = pistol

Can't have a vertical foregrip or a stock on it. Brace is ok, for now.

You can buy a rifle lower but before assembling them submit an e-form 1 and a $200 tax stamp for an SBR, then you can do whatever to it. I did one recently, took 20 calendar days. Was a pain doing my own fingerprints to send in but they made it through.

As far as the Feds are concerned, to make a pistol, you can use any lower so long as it was never part of a complete rifle.

Get a new lower. The dealer should identify it as 'other' on the 4473. You can then proceed toward making an AR pistol with your upper so long as you comply with state and local laws (which, in your case, I'm unfamiliar with).

Once major advantage of an AR pistol is that you don't have to report taking it across state lines like you do an SBR.

Before you attach anything, do some research on NFA so you don’t get yourself into a bind.

Thanks for the replys. I got with my FFL and he laid it all for me. I should have just asked him first!