I mounted an MTAC 1.5-4X on a S&W AR-10. The rifle fell out of the safe one day when I opened the door, but all appeared well until I took the rifle to zero it. I had not fully tightened the cap on the elevation turret, and the impact with the floor knocked it cross threaded. When I tried to remove the cap everything came with it and I vented the nitrogen. I used a hammer to fix the cross threaded problem (didn't know until then what the problem was; a smarter man might have figured it out earlier and would DEFINITELY not use a hammer the get the threads aligned again). I called Burris and 'fessed up; they told me to send it in and they would look at it. I needed the scope for an upcoming rifle class and held off sending it in, but when I did Burris honored the initial documentation from when I first called. They decided the scope could not be repaired and replaced it with a NIB 1.5-6x, which is the current version of the scope I had purchased. I paid shipping to them; they paid shipping to me. I am a fan and will buy more Burris scopes.
Tony