HK G3 or Cetme 45acp Conversion KITS

For Christmas 2024, Centerfire Systems will be carrying our Gen 2 kits that now include an updated recoil spring, to replace the strong HK G3 strong.

The HK 45acp conversion kit is now in stock. This is to  convert HK G3 or Cetme parts kits to use 45acp Thompson M1 magazines. This is a very easy conversion to do, except for welding the trunion into the receiver. This will work just as well with a low cost Cetme kit from Apex and Century Arms or with HK G3 parts. We used a G3 receiver from PTR, HK trigger pack, rear stock and handguards with a Cetme bolt.  This can just as easily be set up with all standard items in the kit or upgrade to a SD front end(still, in the works).  Online instructions to follow.

Update 1. These kits can work with the Cetme/HK parts as either a blowback or delay blowback. With the delay blowback, we will offer a modified locking piece for the bolt. For straight blowback just remove the rollers.

Update 2. Most Cetme/HK parts are interchangeable or can be made so. The one item that must stay as HK or Cetme are the bolts and locking piece for maximum reliability, dont mix the locking piece. For our mixed mutt we were able to get HK rear stocks to work with the Cetme bolt by reducing the size of the washer in front of the recoil spring.

Update 3. Due to the small diameter of the barrels, the cost to machine these was higher than expected and increased the cost of the kit. Expected price is around $20

This first kit features the following.

1. Magazine adapter-100% complete and drop in with built in ejector and mag catch.
2. Barrel with black QPQ (nitride) finish
3. This first barrel is set up for HK length gas tube and handguards only. (Cetme is about .25″ shorter)
4. Kit does not include the modified locking shoulder for the delay system. We are still working on those.

Barrel Thread:  .578 x 28