[Yo-Yo]

The main advantage of building your own is that there is (in most states at least) no official record you have it. Anyone interested can track your credit card history to find associated online orders, but there is no ATF Form 4473.

That is only true if you complete an 80% lower. A stripped lower must be sold on a 4473 from a federally-licensed dealer.

[Pollster1]

That is only true if you complete an 80% lower. A stripped lower must be sold on a 4473 from a federally-licensed dealer.

True. I was thinking "build" as in "machine", not just assemble, but I did not make that clear. Thank you for the clarification and correction.