Guns can be like a fickle woman, they like what they like.
Some guns love the light 55,58, and 60g bullets, others will love the 70 & 75g bullets. The 60g Sierra will not tear huge holes in yotes, and you can hit them in the back of the stomach and they will be DRT. I have shot a lot of coyotes with the 60g Sierra, start off at 46.5g of Win 760 or H414 and go up to 49.0g, stop if you see pressure signs.
I have two 243's that really do not care for the heavier bullets...go figure..
One load that seems to perform in many 243's is 43.5g-44.5g of 760 or H414 with the 70-75g bullets.
Max loads (for that rifle) of IMR 4064 with a fed 210 primer with the 70, 75, and 80g bullet works extremely well in many rifles.
For a longer range load, perhaps the best balance of speed with bullet weight is with the 80g bullet in which the accuracy load is usually in the 3450-3500 fps range on 24-26" barrels.
My favorite load in the 243(if the barrel will shoot the load) for varmints is with the IMR 4064 with the 80g blitz with 41.0-41.5g of IMR 4064 at 3450-3500 fps (work up to that load in your rifle). This load will dump a coyote hard way on the other side of 300 yards, however you have to remember that perhaps 80% of all coyotes that you will kill will be within 175 yards.
I shot p. dogs and chucks with 38.5g of H4895 with the Sierra 85g BTHP, @ 3100-3150(slow lobber load). In the barrels that I have loaded for, it seems as if the speed really drops off on the 85g bullets compared to the 80g bullets.
The best all round bullet will be the one that your barrel will shoot accurately!
Good luck!