I have an opportunity to buy a really nice SBR , however I have no idea how to do this. I know I have to get a stamp for one, and it could take a year or more. So, if I just buy the lower, going through my local gun dealer, and buy the upper in a sperate transaction, and don't mount it on the lower until I get the stamp, is that legal?

Signed,
Don't want to be a prison bitch.