The other train wreck of a thread talking about having an 80% lower finished by someone else without marking them reminded me of this beautiful fail I stumbled across on GunBroker the other night:
https://www.gunbroker.com/item/882626059
"Complete AR15 Milled Lowers... These AR15 lowers are...
Upon closer inspection, I noticed the slide does not have a hole for a firing pin to even protrude through. So even if you replaced the short firing pin with a normal one, it would just run into the back of the slide breech face. Another safety feature surely, to prevent someone from swapping...
For those asking, yes the frame is serialized. It is definitely a gun at the federal level as the frame is all there where it matters and could easily accept a normal Glock slide and shoot.
Here's a fun query. Is a factory Glock cutaway model a gun under MGL? It's not immediately capable of firing shot as the firing pin is intentionally made too short. I suppose if you replaced the firing pin with a normal one, it would fire a round, but possibly blow up in your hand since the...
They don't have any info you don't have. They just decide what they want to sell/transfer or not; it has nothing to do with the law.
I would check in with other dealers.