Yes 308 will give you 3 to 4000 accurate grounds 243 loaded to correct velocity will only give you around 1000 to 1500 .
accuracy level required for 1000 yards plus if you are using something like the burger 95 grain vld then you would need a quicker twist than one in 10 which most 243 Winchester barrels come with I shot 3 243w with this projectile and everyone of them only showed the same 0.410 BC of the 87 grain Vmax if I had of used a more rapid twist barrel I would have got the full I think I will stand corrected on this.45 + BC of the burger.
never buy a long-range product until you do your research simple as that not having a go just my personal opinion because it will end I tears .
Like blade I shoot 22rf out to silly ranges and centerfire out 1800 yards if you would like to discuss this farther pm me a ph # and I can help .
I don't want to come off as someone who is bragging but this group went sub 4 inches.
And you will see it is the original group by the shape of it at the end of the video even though the still picture was taken in the dark reason being I got back up to the four-wheel drive in the opposite direction there were two targets that I shot and by the time I dressed them out got back to the steel Target it was way after dark
https://youtu.be/4HlMxoO27fI