ive had aimpoints on my 44 mag and 2 fa 454 and after firing thousands of rounds they are all working fine. i will have to say that on one the on /off brightness switch became loose , so i sent it back and they repaired in for no charge. i currently owen about 23 red dot sights and have owned probly close to 40 and the aimpoint is the absulate best, for accuracy , and durablity , large field of view, compleatly parralex free at any range , the dot stays on target even if you put the dot on the outside of the lense, the dot is allways perfectly round, and the comp model is compact in size. bob