Short, to 400?

20” minimum for blast and speed to expand on impact on long shots.
6 or 6.5 Cm with heavies made for hunting.
7/08 fine also. 140 AB, 150 NBT or ABLR

243 assuming good bullets - look at a 95 BT

For me- Under 300yd a 223 and 6.5G fine using good bullets.