The ones I bought haven't had a single issue. The primer cups are a little stiffer. But assuming I'm not working with cases that were previously crimped I don't have any issues. But I had heard that some of the earlier wolf primers had issues with contaminated priming compound that sometimes wouldn't ignite. I believe that's what the consensus was.... Either way, any time I've had an issue with Wolf Primers it was a problem that I created myself by not paying attention to detail.