I purchased one of the first batch of the MK11 Mod 0 reproduction rifles Centurion Arms made, been in contact with them about potential causes of this issue but thought I'd ask this sub as well. 

I've been having a persistent issue with kac and pmags where closing the bolt on first round or sometime during a firing string, the rounds will strike the chamber face and jam up. 

Looking around, it seems like it may be a magazine issue but with this issue also occurring with pmags, I think there may be another issue at play. Here's what I've discovered so far:

Shooting a shorter length cartridge like Federal 150 Gr soft point cycles perfectly fine with both Kac and Pmags, but anything longer and this issue where the rounds strike the chamber face will occur regularly. 

I feel like it may be a magazine issue but im not sure to be honest. Centurion says each rifle is headspaced and gauged during assembly so I'm not sure if thats the issue either. I'm thinking the magazines are simply sitting too low. I also noticed one of my kac mags fall out just from cycling the rifle normally, which im not sure if its a mag issue or mag catch issue either but I suspect it may be a sign to the actual issue. 

Let me know what you guys think! I really want to love this rifle but this issue practically makes it unusable with anything but the 150 grain soft point.

Centurion MK11 Mod 0 feeding issues