Heavy C, sounds to me it could be a couple of things. 1. Don't rule out a headspace problem, its probably not, but it could be. I bet after you get enough fireformed brass for the AI it won't misfire anymore. 2. Weak hammer spring. The hammer spring is not hard to do. The gentleman no longer welcome here has a free(or it use to be) downloadable tutorial how to completely take down the encore and change the trigger spring. I've done 3 trigger jobs on encores using his step by step instuctions with no problems. If your gonna change out the hammer spring you might as well change out the trigger spring too. Personally I think after you get your brass fire formed you'll be good to go. Dave