Encoreman, were you by any chance using 777 when it misfired? Theytoidme not to use it with small rifle primers. When I ask if they had a setup for large rifle primers because I had knew of some misfires they said no and cut me off.
I have a friend that is using the 2520 case setup with APP and he loves it says never has to clean any thing but the barrel,that it seals tight.