I had at one time considered the same thing. If you want a long range gun that is easy to carry the .338RUM would be the choice for me due to the cost difference in the brass.
Or, you could go with the .50BMG but they are a bit heavy to tote around. <img src=icon_smile_big.gif border=0 align=middle>

&quot;Lord, make me fast and accurate.&quot;