Here is a case failure I have not seen before. It was the only damaged case of the 60 revolver cartridges I used during a recent match. It's a Remington .45 Colt case that has been fired 3 or 4 times. The perforation is located very close to where the base of the seated bullet would have been. The load was one I've been using for years, a Lyman 454190 bullet (253 grains), lubed with 50/50 beeswax/crisco, 33 grains of Goex FFFg and a Federal LP primer fired from a Uberti-made revolver.
I'm sure we've all seen many split cases before, but have you seen a circular perforation such as this?
