I'm the OP of this thread, I made it because i had moved entirely to 6mm stuff. I wanted DRT to 300 for night hunting, fur friendly wasnt a first priority. I carried a 22-250 for years, lots of experience with it and different bullets. Bottom line, the 243 kills way way way better. You can mix match bullets anyway you want but the results are the same.
Since the original posting back in September of 21, I've killed or seen killed well over 600 coyotes. Most all of them was with a 6mm bullet fired from a 243 or 6x6.8. I've used one of 3 bullets, a 58 Vmax, 70 NBT or 55 NBT.
From my experience and sample size I've came to this conclusion,
58Vmax- they are accurate but sometimes they splash and require a finishing shot, 85% of the time they are DRT.
55NBT- very accurate, built heavier than the Vmax, much more fur friendly, still kills very well. This bullet IMO is the best choice fir DRTs but still somewhat fur friendly at times.
70NBT- kills the best, no question. Almost always exits and usually rough on fur. IMO the best for DRTs.
I guess the reality of these three bullets is they all kill well but you never know how bad the damage is going to be as it can vary a lot. Pick any of the 3 with a 243 and you will have an awesome killing cartridge.