I've been using mostly Cheddites in reloading for quite some time now. Both 12 and 20, mostly in vintage doubles. Can't remember the last misfire I've had, and no problems with primer dragging. That being said, vintage doubles can be problematic for all sorts of reasons. A friend was shooting a Lefever yesterday with reloaded Federals, all sorts of problems opening the gun after firing. I gave him a couple of my STS reloads, no problems. Not a primer drag problem, but obvious difference in rim thickness, the STS being thinner.
