M*CARBO Brotherhood

Cracked plastic by barrel reciever area and tons of light strikes

So i was shooting today for the first time after installing the mcarbo internal upgrade kit and found bits and pieces under the barrel chamber area cracked off, the plastic parts just crumbled while cleaning. Has this happened to ayone else? I assume its still safe to shoot but it was weird. Also had a bunch of FTF with light strikes, like ALOT of them! Might clean the bolt and if light steikes still happen go back to the old hammer spring. Any insight would help cuz im confused. Pics are attached.

All Things SUB-2000!