Talking with a bud in PA this am,I just ordered a 16" 300 blk upper have a few 80% lowers, etc etc, his ? was is it legal to "build and possess" a AR platform pistol with a 80% lower and it be unregistered as the rifles are, been searching but getting lost in the google mess of ads for selling me stuff,or a link to ATF/BATFE and AR platform pistol regs.
thanks in advance