Went to the range today with my CM9 that has been flawless since I bought it...been bragging since I first shot the firearm. Well for some reason the trigger is not resetting all the time. Was about on the first 2 or 3 rounds out of each of the 3 mag I used. Was shooting Winchester NATO... that I have shot before with no problems. Went to Federal and Aqulia same thing was happening. Took the gun apart, cleaned and checked ...can not find any visible problems. Any suggestions as to what to look for in detail?