Out of the 20 or so SxS's I own only the 1873 and one Parker hammer guns right side pierce the primers. I'm not worried about blow back. I wear shooting glasses. How many times has anyone heard of a shooter being injured from blow back ? I wasn't relating the story for a safety lesson, only to comment about Cheddite primers. There are 25 or so guys at my club who order reloading supplies about four times a year. All but one or two guys order 5000 Cheddites, and no one else has had a problem with blown primers. I've gone through over 60,000 Cheddites without a problem. It's only now with one gun that's giving me a problem. I could take down the firing pins a bit, but naw, it's not worth the trouble. I'll just use Federal or Winchester primers. I'd like to thank everyone for their concern about my safety but I'll be ok. Paul

I have trouble with Cheddites pericing on my Kolar O/U. The firing pins hit the primer at an angle and I think Cheddites can’t handle this. I have no problems with Winchester’s or Remington’s.
I have no problems with the same load with Cheddites in my 1100, the primer strike is straight on with that.