Hello Friends: Seeking some help and/or advice. I have an AR lower and want to make a AR pistol out of it. When I got it from my FFL, I told him what I wanted to do and he said no problem. When he called it in , he said it was a receiver and could be a rifle or a pistol. I've heard warnings that if I get the upper for this as a pistol and have a complete rifle upper in the house, I am in violation of the law because I then have an SBR. Would it be wise to complete the pistol lower and then order the upper and when it comes in, put it on the pistol lower right away? What if I still have another stripped lower and complete lower in the house? What about the "kit's" that can be bought for both rifles and pistols, that have everything but the stripped lower? Like the Blackthorne and some other's I've seen. Can you buy this and assemble your own AR, pistol or rifle, because the lower has already been transferred to me. Or will the BATF look at me as a manufacturer. Can I buy stripped lowers, lower parts kits and/or complete kits, and build both AR pistols and rifles for personal use? Don't want the BATF breaking down my doors because I'm making firearms. I already have an AR15 and an AR57. Would like to do a pistolor two and, carbine in 6.5 and/or 5.45. Your thoughts and advice. Thanks. HOOAH!!