Big game should work very, very well. Play with primers, and try some 60g Sierra's if you have any. My 243 Win has zero freebore, and 55 whistle along very well at 4150 out of a 26" barrel.
If you can find any, AA2700 with these bullets has one of the coolest heat indexes of any powder, which means that it burns in the throat much cooler.
Varget worked very well with the 55's, but it is very rough on barrels and tough to get out of the barrel if you like cleaning down to bare metal.
