I'm shooting a 455 heavy barreled rifle although it's 16.5 inches long and threaded. With the Boyds Tacticool stock (now called Pro Varmint) its being used as a benchrest rifle.
I went with the Weaver Classic V-series optic in 4-!6 X 42 with the Fine Crosshair Dot reticle. It also has the Adjustable Objective and semi-target turrets (what ever that means). Its mounted to the 455 with BKL 200 Series scope rings. For my application, its perfect. If you are planning to hunt varmints with it you might want to consider a more traditional duplex style reticle.
My rig is very accurate with CCI standard velocity ammo and it exceeds my shooting skills. I purchased some Federal American suppressor ammo which I hope to test out soon once I get my stock back from the DuraCoat guy and winter subsides for a day or so.
Good luck with your new rig!