No first had observation except what a fried has told me. He had one on a AR in 308 that was a tac driver. It was a very high end trijicon scope, I think something over a grand. He used to do the dial it up and down to shoot out to 6 or 700 yards with no issues what so ever. I think it had a top mag x of 21. Only way you can know what or how well the scope works is run it through the pases by dialing it up down and sideways to see if it will hold it trueness with all the click adjustments. You can do a 20MOA box movement at 100yards to try and test it out and see if it will return to you zero and also checking to see if it dials 20MOA or something less or more. Dial a couple of moa and take a shot maybe every 5 to 10 moa when making your box.