Matt what you are asking is pretty much impossible unless you range and dial. Personally I do not like holdover reticles, but other people really like them.
Something like a VX-6 with a CDS dial, a ballistic app on you phone and a laser range finder will have those baboons looking for cover out to 600yds plus.
im pretty sure I just gave you the numbers showing it was possible. with any of the cartridges I posted at the beginning of this thread you would be able to effectively have a 400 yard rifle without having to aim at the air above a animal. im not sure about the 338 RUM, 338 Lapua and the 338/378 but the 340 WBY is capable of only having 9" of drop at 400 yards which means on most animals you would aim just on top of their back (I don't hunt the tiny 10). for a baboon sitting on a rock you would aim at the head and hit the animal center mass at 400 yards. considering that the 340 WBY is the smallest of the cartridges listed that means the other cartridges would shoot even flatter.
im considering trying a leupold 2-12x42 with the B&C reticle which would have some marks as reference points at long range but ive always been nervous about having extra stuff in my sight picture.