I write asking if there have been any other shooters of .17 HMR out there with consistently split cases? I am shooting an Anschutz 1517DB. I have shot Federal Vitalshok 17 gr. that does not group so well as the CCI 20gr. I am most happy with. Every so often maybe once every 30 shots or more a case splits in the front on the neck slightly. There seems no ill effect, but it obviously is not good. I worry that the chamber will get damaged with time. SO far I have been cleaning only with a pull through, but I have located a bore guide and might try cleaning it with brush and patch. Is there a recommended ammo that I might try, even if it cost more? I love the round and performance, but...... not quite right.