I have a friend that has a SBE 1 giving him cycle issues recently. I own 3of them and dont have issues if I mount he gun corectly. 2 of mine have Sure Cycles. Buddies gun has a Sure Cycle system and he has owned it for years with very little instance. He maintains and cleans it regularly. I tore down the bolt assembly and cleaned the receiver. A small amount of FP 10 on the rails and bolt rotation index the gun was good for one Hunt. 4 Shots no issues. The next hunt same issues. Thinking possible mag tube / Mag spring, dirty or weak spring. Any additional thoughts?