I would leave the 30-06 a 30-06 and just go kill elk. If the max range you are shooting is under 500 yards, you already have a fantastic elk cartridge.
You ought to look up the thread "deceased by Scenar" and see just how effective the 155 Scenars, when fired out of .308s and 30-06s are.
A 155 Scenar at 2900-3000 fps would certainly be plenty.
In spite of what neophytes and flatlanders say and think, you don't need cartridges that often get used for African dangerous game just to shoot an elk. The are really not that hard to kill in spite of BS spouted.
This.
