So I'm working on a buddy's MMR that has taken two trips back to Mossberg. The rifle has actually spent more time there than at his house. The problem has been jamming bullets. Both times the rifle has come back with grease on the feed ramps and no note or any indication of a problem. I took it apart and it looks like the upper receiver's feed ramps are way small and seems like the bullets are getting stuck there. Anyone have this issue? At this point, we are going to ditch the upper receiver with one with M4 feed ramps. I'm pretty sure that will fix it. Any help is appreciated as Mossberg has not been of help thus far.
Thanks
Thanks