Having occasional feed problems, trying to narrow it down to which mags/gun. Let me explain, round is going part way to almost full way into the chamber and the slide is not fully closed so gun will not fire, extractor is NOT in the rim part of the round so I cannot eject round except holding the slide back and shake the gun tilted up at a 45 degree angle. If I remove the mag and pull the slide back the extractor will 'jump' the rim and fully seat the round and fire and extract normally. Originally thought is was a weak old recoil spring, but it just happen on a new wolf 12lb. with 1600 rounds on it. Gun is clean. It has not happened in a match. Yesterday I shot my practice gun with same 3 mags over 200 rounds ZERO problems, shot match gun (same 5.4 sight tracker) and after a few loads 2 mags started having the problem again. Same load, same bullets same everything for over 15k rounds so that has not changed. Only thing I can think of is that practice gun has 13lb recoil spring ( and has more rounds on it) and match has 12lb. Any ideas/solutions? Thanks...