Greetings. I am wondering if any of you are observing any signs of over pressure in your .17 WSM's when fired from the B-mag rifle? I have only fired about 41 rds thru mine so far but have found two cases which split at the neck or near the shoulder of the case. I am not seeing any evidence of then having been annealed like is commonly done with .223 cases and other high pressure bottle neck cases. Being cheap, rimfire, throw-away cases, maybe this is OK? but it was new to me and I thought I would post it here to see if it is common or unique to my gun and ammo lot?

In both cases it was when firing the 25g ammo. I have not yet had the chance to try the 20g ammo. I can imagine that a loose chamber could also cause this but... I am a reloader with many years of loading experience. I have seen similar case failures in both .223 and 45 ACP cases when both loaded to near max and when reloaded many times. After a while they just become brittle and/or wear out. Never saw such failure on once fired brass.

Irish