When I fire my M305 MOST of the time the magazine will disengage and drop down just enough to not feed the next round. Visually you can't even tell it has dropped. When I slap the mag home I've even tried to pull it out just to be sure it has seated properly so yes it is engaged. This happens on 3 different mags so I doubt it is the mag. Any chance the return(?) spring on the mag lever is to weak or should I look to something else. Many thanks for any advice.