Four favorites that shoot well from a Ruger American Predator (RAP), a Savage 110 with a BHW 22" barrel, and a Forbes .243AI.
75gr Speer Varmint HP, 49.0gr Superformance, CCI-200, COAL 2.640" averages .5 MOA from all three rifles
75gr Speer Varmint HP, 42.0gr IMR-4350, CCI-200, COAL 2.640"
or 2.590 (found that one by accident
) averages .75 MOA from both .243Win rifles.
70gr Speer TNT HP, 41.0gr Varget, CCI-200, COAL 2.625" Last range outing with this load produced one 5-shot group that was 0.625 with four of those inside 0.257" from the RAP.
70gr Speer TNT HP, 46.4gr H-414 (W-760) COAL 2.625" Sub-MOA from both .243 Win rifles.
For shots over 500 yards I use a 105gr Lapua Scenar, 41.5gr IMR-4350, CCI-200, COAL 2.775" which is another sub-.5 MOA load in the RAP and the Savage 110.
I do professional predator control and put a lot of rounds downrange every year. I'm not saving hides so, mostly, I don't worry about exit wound size.
For those times I need a no-exit shot I rely on my .223 with 50gr Blitz bullets. I wish I could find an accurate .243 load that wouldn't exit then I could just rely on one rifle.
Hope this helps!
Ed