If a friend of mine was to consider converting an AR pistol into a Short Barrel Rifle (SBR) and screwing a Suppressor on the barrel, would it require one (1) or two (2) $200.00 stamps?
The SBR conversion would simply be addition of a rifle buffer tube/stock assembly.
Two stamps unless the upper has an integrated suppressor (but then you couldn’t legally separate the two). One stamp would be for the lower and the other for the suppressor (the parts with SN’s)
Cheers,
Craig6
That’s what I thought - my friend isn’t going to like the answer 
Any particular reason he wants a stock instead of brace? I have 10.5 in barrel pistol that uses a carbine length gas system and buffer tube. I took the stock off and use a brace. If feels just like my 16 in rifle just lighter. That could save some tax stamp money and a pistol is way easier to transport than an SBR (from what research I’ve done)
He has the KAK Shockwave Brace and says it “sucks”. I think he is trading off ~$150.00 to try a better pistol brace vs. ~$250.00 for SBR stamp, buffer tube, and 6 position stock.
Which brace are you using?
SBA 3. Fits mil spec buffer tube. I dont feel a noticeable difference between it and a stock.
I agree on the Shockwave, I had both the fixed and the 2.0 and got the SBA3 as a Christmas gift, well worth the $$$$ but you have to leave the velcro on. That said the nice thing about SBR stamp is that with one receiver you can do doggone near anything to the uppers. The only thing better would be an M-16 lower or auto sear, albeit a bit spendy if you can find one, as I understand it with an MG Stamp you can configure it anyway you want.
Cheers,
Craig6