Sounds to me it wasn't adjusted right.... I've had some case head separations lately on some PMC 223 brass...
Re adjusted the die and the problem disappeared.....
and 15 firings like my friend Flintlocke speaks of, Proper care, I get at least 3 times that number or more...
My preferred method of resizing a case, is the Lee Neck Collet Die and then a Body die, Anneal it each time, and show a little prudence on the powder scale, and one can get a lot of mileage out of brass...
