You might consider the Aimpoint Micro. There are 3 models, of which two appear very similar (R-1 and H-1)and the different one is the T-1 variant that is a bit more water resistant and has an IR dot for NV gear as well.
I have them on two AR15s and one Marlin 1895 in .45-70 and am quite pleased with them.
"If you look through your scope and see your shoe, aim higher."
-- said to me by my 11 year old daughter before going out for hogs 8/13/2011