I am looking at a Sig SBR lower for sale. My question is this. The lower is an SBR lower. I do not want to use it as an SBR but simply use it with a 16 upper. Can I purchase this and use it on a 16 upper without a Tax stamp? I have heard the FFL needs to send a letter to the ATF to take it off the register. Is there a waiting period if letter is sent in to ATF to take it off the Register? Its a new upper and not registered.
