I recently purchased a montefeltro sporting. I'm experiencing about 5-6 malfunctions per 100 rounds. Ammo is Winchester super target 1 1/8 oz 1145fps. I have added a mercury recoil reducer in the butt and a weighted magazine cap. Would either of these affect reliability? I fired about 400 rounds trouble free before adding the weight. I also purchased a fresh lot of ammo when the trouble started. Should I move up to 1200fps? Any thoughts?