Not to long ago I posted that I was having issues with my new at the time 20 GA Pardner piercing primers on Remington ammo. Since that time I bought and used some Winchester 7/8 oz. game loads and slugs. To date I haven't had one pierced primer on the Winchester ammo. The Remington game loads are hit and miss, I'll get a pierced primer and go 1 or 2 shots then get another. So it appears that it is a ammo issue and not an issue with the firearm.