texashunter58 has some valid points. I think the break open action on the Omega, Optima, Beartooth Magnum, and some of the new ones coming out, are sure a nice feature. I have the Black Diamond like I said and a CVA Staghorn. Both of them are great shooters. But if you like the style of the Optima Pro that would be a good long range rifle. I personally would get the .50 caliber. You can always load them down.

A lot of your range will have to do with the projectile you select. For that I would go to Precision Bullet and check out their Dead Center Sabots or QT40's. I think that is one good long range bullet. I shot some of their Silver Lightening 300 grain and the group they shot was outstanding. It is the cost of them that makes you kind of look hard at them....