Forgive the ignorance, I have attempted to search this out:
I am trying to get a clear understanding of the HK multi sear.
In the other topic of "If you were to do it over again..." it was made mention of the multi sear and the possibility of using this sear for more than one gun.
After looking into this, I found in other forums, discussions related to this topic where form 4 was registering the multi cal sear and the gun. It was my limited understanding the sear could be the registered part, and the "host" could potentially be many different guns (as the point of a multi sear).
However, I also found that the host gun is not as simple as "drop in multi auto sear" to make the host an MG. Therefore, a host would not be an "off the shelf" HK 91, or say a PTR 91...etc and it would require some modification to accept the multi sear. True or False?
Also, it was mentioned ATF no longer accepts "multi" in the box for caliber, and doesn't want more than one caliber in the box.
So, to wrap up the ramble... If one posses the HK multi sear, could the multi sear be placed in other non NFA HK (or HK like products) to then create an NFA MG without registering the firearm as a unit?
Could this be possible with only the sear as the registered NFA item, and the hosts as reversible semi to third position? If true, it goes to reason one could then obtain non-NFA hosts, and convert them at a much lower investment.
Clearly, there is an advantage to this, if it is remotely true. But, something tells me this aint as easy as it seems. Reuben, subguns and sturmgewehr all ask a premium for the host and sear.
Help me understand.
A registered full-auto HK trigger pack can fit any semi-auto HK style rifle without modification. All you really need is to have a full-auto bolt carrier to trip the auto sear in the trigger pack. You can use any real HK or clone and it should work fine. Of course some clones don't work perfect out of the box so you may need to get them running reliably first. You can get just the registered HK sear also, but then you will need to setup the trigger pack properly for it, you will need a re-timed hammer most likely. I think it's better to get a registered trigger pack that's already setup with the sear, then it's just plug and play. Of course if you want the option to use either the SEF or Navy style packs then you will need a registered sear, since most the registered trigger packs are SEF and you are stuck with that pack. When I say triggered trigger pack, what I mean is the trigger pack housing has the serial number on it and is the registered part.
I have a Cohaire HK-94 clone, Vector HK-93 clone, and a HK-91 that I've used with my registered HK trigger pack. I plan on getting more hosts also
As far as the Form 4 goes for caliber, say you bought the host and trigger pack together, then it would be the caliber of said host.
But yeah the HK sear and M-16 RDIAS are the most versatile of all the registered machine guns out there, lots you can do with them.
There is good info above, but just an FYI, the ATF allows multiple cals on the HK sears. I've got four listed on mine. They don't allow "multi" on SBR's. Well, they might not allow it on the HK sears now that I think about it, as in putting "multi" in the cal box. Put .223, 9mm, .308 and it'll get approved.
Thank you. All the information is very helpful. The above link is very thorough, and complete.
You are all good men, and thorough.