So if I purchase a registered fleming sear that has been installed in a trigger pack.  I can use this in a semiauto rifle by just changing out the pack and adding a FA bolt and carrier in a HK weapon?  

Dont you need different packs since the spring rates are different in 91s, 93s and 94s?

Once the sear is set up in a trigger pack (A modified semi auto one that fits onto the ledge), all you need to do is swap the hammer spring and ejector lever depending on the caliber of the host.

Hammer springs are the same for .223 and .308, but 9mm is different.  The 9mm hammer spring is longer but a lot weaker than the rifle hammer spring.  The rifle hammer spring is made of thicker wire and is shorter, yet stiffer.

There is a unique ejector lever for each host.

It onle takes a minute or two to swap the parts.

Most people just leave the rifle hammer spring in all the time, even when using it in a 9mm host.   It works just fine for me, and it slows the rate of fire just a bit.  I think that is desirable because registered sears tend to run a little faster thatn true factory MP5s.

Hope this helps!

You also need a grip that has been "clipped" to fit the ledge on the semi guns.

"Clipping" (pic) is a process of removing material from inside the front of the grip to accomodate the wider area on the semi guns.

And don't forget to flatten/remove the selector stop "bump" on a semi grip housing. This will allow the selector to rotate further. You may even want to make a new dimple for the auto position.

HKO

Thanks guys thats the route I want to go once this Michigan AG thing is ironed out.  I have a sp89 and 94 that are screaming for a sear.