The Milatary uses the Super Sniper on a lot of the 50cal's. I have also see one mounted on a 40mm. It is a fixed scope though that is why it works so well.

I love them i had one for a long time but someone did not like it so much and shot it with a .22 good thing i know how it was. Took there gun and though it into the furnace i use when i do metal working lets just say it shoots to the right now.