RE: remington 40XB
Personally, i think "IF" you haven't already been shooting groups for quite a while to know how it's done, you'd be better off with a 700 varmit. They can be tuned up to shoot very very good!!! Why burn up a "premium" bbl. learning to shoot groups???
Once you have all the gear, and have some experience, then use the varmit to build a custom on, or just plain build a custom on a diff. action.
Drilling Man