Quote History Originally Posted By MCW:
Both of us contacted the tech department.
We were told to use "hotter ammo."
It is not an ammo issue. The spent case is being dropped inside the receiver. It is not ejecting from the gun.
The spent cases are extracted from the chamber and then dropped into the magwell/breach/receiver area.
View Quote
Have you seen this thread?:
https://www.ar15.com/forums/ar-15/Thoughts-on-the-CMMG-Guard-/15-713060/&page=20
It would be great if you could chime in over there as the more data the better.
Several of us are having issues with the ejector spring failing at around 1K rounds.
I have done a lot of testing and documentation here:
http://c3junkie.com/?page_id=954
The factory CMMG RDB ejector spring is shorter than a standard 556 spring but the coils are thicker making it stiffer/stronger.
Maybe someone assembled the bolt by accidentally using a standard 556 ejector spring.
In my experience, once you start seeing under 5lbs of force to compress the ejector spring flush with the bolt face, you will start having FTE's.
How many rounds have you fired?
From your post it sounds like it is new? Or new to you? Previously owned?
If brand new, maybe the BCG is binding in the upper? If you remove the upper from the lower, does the BCG move freely in the upper?
Longer 9mm buffers shouldn't be used in the CMMG RDB due to the bolt / carrier relationship.
What kind of buffer and spring were you initially trying to use?