I'm talking about deer in Texas, medium size mule deer, antelope, etc. I would like to know what kills you've made or seen made with the 243 and what bullet on them? I'm just curious as I don't like to shoot past 250, even though I have shot small antelope ( Blackbuck and Springbuk at 375yds with bigger guns) I did kill that big Scimitar horned Oryx at 184 yds with a 243 equivalent (long barreled 6x47 with 85 XBT going 2900fps, base of neck shot) Or hogs even?
For Texas deer, you can be confident at any range at which you can keep all of your bullets on a luncheon plate. Depending on where you are, that may be just about the size of a deer's chest, especially in areas where there are lots of deer. Although they may run a short distance with a chest shot, that is the one that has the most room for error. A Texas whitetail's neck may be about the size of your forearm.
I prefer to use the heavier bullets in standard cup and core designs (90 grains and up) but I think you can do well with lighter bullets if they are partitions, monometals or bonded.
It's still all about bullet placement, so to me the limitation is the maximum range at which you can reliably put that bullet where you want it to go - through the vitals. Any 6mm will be deadly at any range at which you can do that.
Now if you come across hogs, you'll probably want to shoot for the head...just sayin'