I purchased the 4×16×42 Blue Diamond and mounted it on a proven to shoot 300 RUM I wanted to maintain a low profile more compact hunting scope that would fit in a standard scoped rifle scabbard while hunting a horseback. The 4x16 fit the bill perfectly. The videos on YouTube were very helpful in collecting the needed rifle data for the custom turret inputs as well as how to properly mount the scope and get started shooting with it. (Take the extra time collecting accurate data for your turret as it will be etched in it for all eternity so to speak) Once my custom turret arrived I just popped er on, and the scope has performed consistently out to 1000 yds on the bench. The clarity in glass is excellent and it performs well even in low light conditions. the yardage/windage adjustments are all right there on your turret. I havnt taken any super long rang shots while hunting but it sure made the 3 and 400 yard shots that I did take a slam dunk. One of the best scope I've ever owned.