LuckyDuck

I just bought a new M2 12 ga. and shot it for the first time this weekend for the opening day of Dove season. I was shooting Rio game loads (2-3/4", 3-3/4 drams, 1330 FPS, 1-1/4 oz, 7-1/2 shot). The first shot goes off fine. The shell ejects and the bolt closes, but successive shells are not feeding consistently. The second shell end up either still in the magazine or winds up between the bolt and the lifter. I switched to Winchester low-brass target loads and shot 2 or three boxes with no problems. I also shot a few federal high-brass sheel shot with no problems. I also encountered the problem where, the second and third shell shell could not be loaded into the magazine consistently. The shell binds sometimes to the point where it cannot be inserted into the magazine. When they can be loaded into the magazine, the fit is very tight. We tried the Rio shells in a friend's Beretta 3901 and they worked fine. When I compare the Rio shells to other 12 ga. shells, the base seems a little different - the brass rim that seats against the chamber opening is a tiny bit fatter, causing the shell to not go into the chamber in quite as far as other brand shells. Has anyone encountered problems with Rio shells in their M2?