Brethren Armament Fixes the MP5 Trigger Pack, Now Takes AR-15 Trigger, Safety, and Grip - The Truth About Guns
ATF form 4 a mp5 pistol to make it into a SBR
then get a slide fire stock on it
surefire was a mistake sry
HK HK HK HK HK HK HK .. U.S.A Hidden Content
I would personally go with the sear because then you have options. A Form 1 to SBR the current host isn't a big deal. When you're talking machine gun prices and extra $200 for the SBR stamp is nothing. If that was a push pin registered receiver you would have a better argument for the registered receiver, but personally I'd still go with the sear. When the bug to shoot something else full auto you only have to find another host instead of another machine gun.
A 10% difference between an unaltered semi auto registered receiver converted with an unregistered sear without the original conversion parts and a registered sear? Either the sear is way below market value or the RR is way above market value. An unaltered semi auto registered receiver converted with an unregistered sear without the original conversion parts would be the absolute least desirable HK full auto. If you want a four position ambi group for the sear, I'm sure MM could do it. Be fore warned, my brother bought a sear that had never been in a pack. He spent almost $1,000 for the ambi burst tripper group and having a smith install he sear in it for him. He said it was cool when he first set it up in a host. Once he learned trigger control (it is possible to get consistent single shots even in a "K" gun with the selector in the auto position), he only uses the burst position when taking a newbie to the range. I have a SEF set up. I simply start with 3 rounds in the mag. Then I go to 5 rounds. Once the shooter can manage two bursts with 5 rounds then go to 10. From 10 go to full mags.
When I bought my sear, it came to me "married" to a Vollmer converted 94. I didn't have any intention to "divorce" the sear from the host as I had a DIAS for the M16. I was busy coming up with all the variations for that. I got to shoot a 53. 5.56X45 NATO is basically .223 Remington with a little higher pressure, thicker brass, and heavier bullets. To be clear, it is my understanding that a sear came be installed and used in whatever caliber, as it is only temporary. The 53 was a lot of fun. I now have at least one of 53K, 53, 33K, and 16" 33 (Century C93 that I don't shoot much) for 5.56X45. I've really gone in for the pistol caliber stuff. But that is another story.
As far as values, once upon a time, it was push pin registered receiver, unaltered semi auto registered receiver converted with an unregistered sear, and the sear was at the bottom. The sear is now at the top of the heap and still climbing. Why, the versatility. If I had unlimited funds, it would cost over $3,000,000 for me to have pp RR guns to replicate all my hosts that I use with my sear. Since I only shoot one gun at a time, one sear is all I need for roller locked machineguns. It seems with the values of pp RRs they are even more of a "collector's item". Your money, your gun. But to me the unaltered semi auto registered receiver converted with an unregistered sear, especially without the original conversion parts isn't even in the same league as the sear gun. The unaltered semi auto registered receiver converted with an unregistered sear RR machinegun is a collection of parts. It doesn't have the original parts. That is nothing I would ever own unless I could buy it for the price of a converted 94 SBR. Again, your gun, your choice. YMMV.