Sounds like there is something under your Platform not allowing it to go all the way down. ARE you using the proper size of primer inserter LG/ SMALL .??? Have you changed brands of primers just to see what happens.??? High primers is one of the MOST dangerous things you can have. This can cause the cartraige to go off before the bolt is closed and a shell going off when not in battery is,,, BLINDING for you and others. High primers in a revolver can LOCK the gun and you will not be able to get it open. You should be checking ALL you loads before using them. Danger Danger DANGER