I have a Rapid Fire 51 clone that I had them do with a full 16" barrel. I love the gun and it shoots 100% reliable.  I have done the SBR thing to a couple guns now and I think I am hooked. I keep entertaining thoughts of SBRing my 51 clone.

Will I need to tweek it to run after the barrel is shortened?

I have heard that this can be done by removing a few coils from the recoil spting, but when I first got the gun this had already been done...it fired fine, but wouldn't have enough force to strip the top round on a full mag...fine with 18, but 20 was no go....I put an un-cut 91 spring in it and now it is perfect.....just looking for input here.

I don't want to have a very cool looking (in my eyes anyway) gun that doesn't work for shit.

Added.....pretty much the same question with my 16" barreled 53 clone also.

You should talk to Brian at House of the 51 www.hot51.com/

He's probably the most knowledgeable smith on Hk51 builds.

I checked his site and he's gone until 3-25-05..I'll check when he gets back. Thanks for the lead.

I have heard that this can be done by removing a few coils from the recoil spting...

Been talking with Bubba again?  

The correct way, if I'm not mistaken, is to use a different locking piece.  The angles on the locking piece control the "leverage" exerted by the chamber forces over the bolt and recoil spring.

Been talking with Bubba again?

Actually Todd Groove (owner of Rapid Fire) told me that......but I agree, it isn't probably the correct way to do it.  Nothing against Todd G....he is a great guy. I understand about the different locking pieces, because I have a PDW semi-auto and I know that has a different one to make that run better with the short barrel. Do you know what particular locking piece I would need to look for? Or is is just a 51 locking piece?

Thanks in advance.

A G3K locking piece and a standard HK91/G3 recoil rod, unmodified.  Cut the Barrel, thread it for a flash and you should be ready to go.  Don't forget to get the correct HK53 wide forearm to replace the HK94 ones that are so often used.

Mine started out life as a HK91, so I had to do quite bit more than just modifying the barrel.

Are G3K locking pieces hard to find? $??????

I have a 53 forearm.

If you decide to go with a Hot51 build, Brian will custom grind a G3 locking piece to match the gun. He will also modify your recoil rod/spring for about $25.00

HTH