I put one of the new Trijicon 3-18's on my main rifle (7mm Mashburn Super) and couldn't be happier. Amazing glass, adjustments are on point, illumination is real nice and the reticle is excellent for shooting.
Scotty, how much does that one weigh and is it a FFP or SFP scope? 3-18 is a great power range. Very versatile for sure. I imagine it would work great for the OP's 400+ yard requirement, as long as it tracks well.