Bought the Stainless Steel Heavy Barreled Mod. 93R17 in 2008. Been very happy until now. I have run about 2000+ rounds though this gun and recently I have experienced miss fires and split cases (neck area). I'm very finicky about cleaning and maintaining my guns. My first thought was to thoroughly examined and cleaned the bolt, but I'm still having the same issue. The bolt and specifically the firing pin look to be in good shape with no signs of excessive wear. It's not the ammo. because I have tried 3 different flavors with the same results. Could the headspace have changed? If so how and what can be done about it. Your thoughts please.