Cases weren't the problem. I tried an assortment of rifle and pistol cases; I have no steel or aluminum cases and no cases with crimped primers that had not had the crimp removed. The tools just didn't work well.

The best priming tool I had was foolishly sold several years ago when I got rid of some benchrest stuff: a Sinclair.

In the interim, while searching for a good priming tool, I've been priming rifle cases on my Co-Ax and it works very well with a "feel" for seating. Handgun cases are primed on my '60s-model Texan turret. It also works very well. I had forgotten just how well. I began priming cases in this manner in 1965.