first legal section post so dont blast me right off the bat if i dont know what im talking about....but its my understanding that when it comes to anything open-bolt firearm related, if it wasnt made before 1985ish, whenever the ATF put the kibosh on new production open bolts, then its illegal to own as itself is regarded as an MG...

that brings me to the AR platform and open bolt things made for it...i saw that some open-bolt AR parts were up for sale on a website, starting with the upper, bolt assembly, and fire control group...pretty rare stuff, but is it legal to own as-is, or would ownership of the bolt assembly and/or fire control parts constitute ownership of an MG itself, requiring proof of something like a registered LL or a registered lower?

Chevron is gone.

They are not machinegun conversion parts and ATF has never considered them to be regulated parts.  Just like M16 fire control groups are perfectly legal to buy and sell, so are the open bolt M16 parts. They still need a registered M16 lower with the third hole to function as a working firearm.

Legal to own.

ATF never put the "kibosh" on new production open bolts. They named a few as F/A, but you can still make/MFG new open bolts if they are not easy to convert to F/A.

Parts are not conversion parts and not subject to MG definition.

i guess what's easy and "not easy to convert to F/A" is all subjective and relative then...i think it would stand to reason thats why they just put a universal ban on open bolt parts

anyhow, some people seem to be getting offended by me asking this question here, so if a mod wants to step in and lock the thread, go right on ahead...

So can you legally purchase a sear for an M-16? I was also under the impression they were a regulated item

You can buy the OE auto sear. what you cant buy is a drop in auto sear, as that is a conversion part. If you dont have a registered lower, the oe  is useless until you have a 3rd hole.

Roger. Kind of what I thought but you just don't see the parts kits w/sear sitting on tables ay gun shows anymore. But in all honesty, I hardly ever go to gun shows anymore

Yes. You can purchase a M16 sear through the mail. I bought one from armsunlimited.com awhile back.

A DIAS is different because it's a conversion part.

I remember when you could order DIAS from the back of SOF magazine

As others said, there is no ban.

Factory sear is not regulated. Conversion sear (DIAS) is.