I had a 243 case separate today.About 1\3 of an inch above the case head. Lapua cases,the 10th firing. They have been annealed twice,the last time between the 8th and 9th firing.41 grains of H4350. Pushing a 105 bullet at 3000fps. Anybody else experience something similar?Thoughts? Also this is about #700 in the round count with this load, so it is not new.
