Used my 7.6gr of 4227 with WSPM primers for a IDPA classifier yesterday. Couldn't go more than 12 rounds without unburnt powder getting caught under the ejector and causing the cylinder not to close and or rounds not to chamber all the way. It was a major headache and pain in the ***. However I loved how it shot and the accuracy was good. I'm thinking of only using this powder for 357 magnum loads now and not for competition other than pin shooting.