Machined and properly heat treated from ordnance grade steel.  A definite must have item that is used in conjunction when using a suppressor and 147 grain or heavier ammunition.  Each 80 degree locking piece for the MP5K-N or MP5K-PDW models.


RCM strives for the highest quality parts and has been for over 20 years. That’s why we don’t cut corners on material selection, manufacturing processes, Q/C standards and customer service. We don’t try to compete with other US made parts. We compete with genuine German Parts. That’s how high we set the bar for ourselves. There seems to be some confusion with swapping out one locking piece with another and not expecting the bolt gap to change. Well it does! This particular locking piece is for a PDW/K platform with a suppressor mounted on the end of the barrel or heavier loads. Your bolt gap will change and it seems to vary on the brand of the gun and the quality of all the parts that were used in the assembly. You can take a brand X gun that has part tolerances all over the place and when you press and pin the barrel then set bolt gap with brand X parts it will most likely perform. How good? That’s hard to say. Now you swap out the 110 degree locking piece with the 80 degree and some will perform with a larger bolt gap. Some will use different rollers to bring it back to nominal. Some will see such a huge gap that even -8 rollers won’t help. Now your cussing out RCM for an out of spec locking piece because your bolt gap is way off the charts. Well folks now your seeing the flaws in the build and in the parts. Now if your trying to figure out how to resolve this issue you only have one choice. Repress the barrel using either a German Bolt Group or a RCM Bolt Group. BUT take this in consideration. Even in our German guns the bolt gap changes when we change out the 110 locking piece with the 80 degree and both are factory locking pieces. There are so many variables to consider on every piece that makes this gun work. Every part has a tolerance and think of all the parts that create the bolt group. Stack all those tolerances up and if it exceeds the smallest roller size to adjust for it then you will have issues. RCM is not perfect in any regards but focuses on idiot proofing the process to prevent out of print parts getting through. If you feel that something isn’t right give us a call.

**PTR BOLT HEAD NOTE** We are getting lots of emails from customers regarding the issue with our locking piece not fitting in a PTR Bolt Head. Its because the PTR Bolt Head is up to .007 undersized in the Locking Piece Pocket . RCM has no control of the quality standards of PTR. We suggest you grind or mill it to the dimensions of your bolt head.

For these platforms:

  • MP5K
  • MP5K-N
  • MP5K-PDW
  • SP89
  • Other custom builds or clones

2 in stock

SKU: RCM-GP-LP90 Category:

Additional information

Weight 0.4 oz