I think you sure be totally sure that it was bad primers that caused the erosion. Over length cases or severe copper fouling can cause high enough pressures to blow a primer and cause erosion. Case length gauges and a case trimmer are your friends. So is Wipe Out and some elbow grease. Fix the cause, not just the symptom.
If you do a search about Winchester large rifle primer leaks, you'll see it's not a problem of headspace, etc. It's a known problem of weak spots at the corner of the primer face and the primer edge. I have a couple of rifles with etched bolt faces that occurred with starting loads and spotless bores (I call it "Wipeout clean"). I was really questioning my loading procedures until I started seeing other examples (photos) of the exact failure I had experienced.
