I think I know the answer but not sure I'm current.

I'm an 01 FFL, not a manufacturer. But I pay an annual SOT so I don't have to pay NFA taxes on each individual item.

This means if I purchase a SBR from a manufacturer, it comes on a Form 3 and I don't have to pay the NFA tax because I'm a SOT and pay an annual NFA tax.

But what if I form 1 a SBR? Am I no different from non licensee's and I pay a NFA tax on top of my SOT tax?

In the past when I have done SBRs, it usually required some kind of gunsmithing so I just sent things to a 07 / SOT, they registered the SBR and did the work and it came back to me on a Form 3. But this time I have a project that requires no gunsmithing of any kind, just registration before final assembly can begin.

It still might be cheaper to send it out to have somebody do nothing more than register, engrave and Form 3 it back to me but if I can do it myself I'd rather do it that way.