The problem isn't pulling the trigger in dryfire, its a patience issue trying to rush to beat the timer and firing a shot without an acceptable sight picture. I would try dryfiring for a week or so not using a timer, keep doing the same drills you have been doing but instead of trying to rush to beat par times work on only firing acceptable shots. Make sure your not disturbing the sights at all when you work the trigger. Sent from my iPhone using Tapatalk