We have 2 rem 600 Mohawks, both 16" barrels, one 243 one 308. That 308 kicks like a mule, more felt recoil than a heavier, longer rifle in 300wsm. I put a deceleration pad on it, but it's significant, especially considering my 16yr old daughter shoots it. I loaded 165 HP SGKs because I have a lot; it would be better to use 130g TTSX for less recoil. Here's a deer she shot this year. The 243 kills well and has less recoil, but it doesn't do this. IMO ballistics are immaterial for the OP's 0-400yd range, but our 243 can't generate the velocity to overtake the 308 at 16" of barrel. 308 130g TTSX are 2900ish in that rifle, and 243 pushes an 85g SHPBT at 2950 or 100g SGK at 2800. These are the most accurate loads, not the fastest.