On my MK3 I went cheapo. I bought a BSA Reflex at Midway that was on clearance for $45. It's been going fine for 2 years, .22s aren't that hard on optics. If you want something more substantial, check out the C-More Polymer models. For around $200 they are a lot of optic for the money. I stuck one one a S&W 627, around 8 months and counting. I did have a Burris FastFire 2 on the S&W for a while. Great optic, but I found it hard to pick up quickly under recoil. Though on a .22, it will probably work fine. It works better for me on my CX4 carbine.
MSgt, USAF, Retired
NRA Life Member
The hardest thing to explain is the glaringly evident which everybody had decided not to see. - Ayn Rand