[KSR]

OP, the best you can get is an Aimpoint. It'll run you more than the rifle, but you'll never have an issue w/ it - other than it fogging up if it was dropped.

I don't recommend it, but that is about the most money you can spend on a red dot, and it's really clear glass. I suggest you set a budget of what you're willing to spend, and if you post that number, you'll get all kinds of suggestions between that number and about 50% more - so you should really post a number that's about 66% of your true budget.

I think a $400-800 Aimpoint may be a bit excessive in this application. I would suggest checking out some of the Primary Arms options.