I have shot 3 deer at 285 to 300 yds. with my Browning BAR in 30-06. I just ordered a 20 MOA Picatinny rail from EGW to put my Vortex 6-24x50mm PST FFP MOA scope with a custom turret made for my 6mm Norma BR. It looks like the ark of the two calibers may be within 2 inches of each other. I am going to test shoot it out to 400 yds. with the new setup to see if it will be accurate enough to use next year in Wyoming.
I'd rather not carry my 15 lb. 6mm Norma BR. and the 30-06 will give me a lot more poop at longer ranges than the 6mm.
PS: My BAR shoots less then MOA at 100 yds.