I have a 16" DPMS upper with a bull barrel that I purchased used this year and put on my EA lower. The bolt I am using is out of the EA upper.
The problem is that I can put in 5-20 rounds of 55gr. UMC ammo and it works fine 99% of the time. If I put in Norinco or my reloads it will leave a stuck case in the chamber and the extractor will tear part of the rim off the case 50% of the time. Once in a while it will do this with the UMC ammo. All of this ammo shoots fine in my VSS Rem 700 and my Eagle with a match upper. My reloads are checked in a case gauge. I have even tried my Eagle bolt in the EA. Do you think this is a tight chamber issue? The guy I bought it from said he shot 100 rounds of .223 and 250 round of .22LR. I have cleaned this gun 5 times using Hoppes, Sweets, and MPro7 thinking that I had a dirty bore or chamber.
Any suggestions are appreciated.