25-06 Remington
270 Winchester
30-06 Springfield
Depending on the twist of the 243 Win you may be able to use it, but I doubt if it has a 1-8 twist.
Then if you wanted to chop and recrown a factory rifle barrel:
7mm Rem Mag
280 Rem
300 Win Mag
My favorite in the group would be the 280 (chopped/recrowned) pushing 162 A-Max's or the 175-180 VLD's (for instance Berger 7mm 180 grain BC .698) depending on twist rate.
Out to 1k the 162 A-Max would be the better choice than the 180 Berger since wind defelction is all but the same, the 162 is flatter. When you start getting beyond 1k it becomes all about BC as one MPH wind changes will move bullets 2.5 feet at the one mile mark.
25-06 could be real good to depending on twist rate.
The 270 Win & 7RM are surely up there, but there are not a lot of great high BC bullets in 270 but some (Horn 150 SST .525 BC

, 150 NBT .496, 135 SMK .488)
I'm talking about ranges out to 1K or a little further.
The 7RM would be the king as long as you are content to not run it as hard and just look for the most accurate load. You may not get that much better performance out of it for the extra powder and you cannot run a 7RM as hard as you can a 280 Rem in a Encore (been there and tried that

).
All listed will get to 1k.