What type of powder charge are you running compared to similar weight conventional core bullets, we took a proven load out of the book 56 grs of reloader 22 along with 58.5 grs of Winchester WMR powder behind 115 to 120 gr nosler and hornady bullets, he's been using both powders for a number of years, with a 10 gr lighter bullet he reduced the powder by 2 grs for the reloader powder and 3 for the Winchester and blew primers in both, all That's on me I was convinced that was going to be fine, the bullets were mine but I'm was not planning on shooting them just yet so I gave them to him to try, I felt I was being more than cautious which certainly proved wrong, so rather than waste time bullets and powder figured I should just ask.