I am wanting to change to a long range scope on my Ruger M77 .300 Win, maybe a 6x18 or 6.5x20. I currently have a Leupold Vari-X III 3.5x10. I like the features and price of the Burris Fullfield II 6.5x20-50mm but am not sure if the eye relief is adequate for the recoil of the .300 mag. I...