You will be better of sticking with a 40mm objective on any scope you buy. THe 50mm will require you to elevate your head more to see through, and with the ultramags recoil, this could be a consideration. I also like Leupolds long eye relief, for the same reason. You don't really need a 50 anyways. The feild of view and low light transmission will be fine on a quality 40mm. As for reduced loads, you will be having to re-zero and re-learn your tragectories. Stay full power and use a sissy pad or bag of lead shot on your shoulder. Also consider putting on a decelorator or R3 recoil pad to replace the factory hockey puck.