The better caliber for long range varmint hunting would be something in a 6mm as evidenced by the amount of varmint bullets built for this caliber plus the high BC’s that help you buck the wind at distance. I effectively take PD’s out to 550 yards with my .223 AI and 50gr BK’s over 28.2grs of XBR. I also use a 6-06 for PD’s with 70gr Noslers over 59grs of H4350 @ 3700+. My 6-06 is too much for a dedicated PD rifle and would move towards a 6XC then the smaller brothers like the 6RB, 6x47, 6PPC & 6Dasher for a PD rifle or the 6mm Rem or .243 for factory loads.
If you’re really into PD’s then have a 20BR, 20XC or 20x47 built for the 55gr Bergers. Guys are taking PD’s out past 1000 yards with a 20BR and that bullet combo because of its super high BC .381. Not the splat factor that you get with a BT but a lot more enjoyable to shoot because of recoil. I use a (80% of the time) 20VT in the PD fields and don’t need to worry about barrel heat or recoil (see my hits every time) 32 gr’s @ 3700+ with 18grs powder with a BC that rivals most HP 50 & 55gr .22’s
I would also try getting one of your 22-250's to shoot the new 53gr V-max's with the BC of .290. That should make your current rifles 600 yard rigs with no problem. You will need a 1:12 or slower to make it happen. My 1:14 just wont get them to fly along with many of my partners.
My current 3 varmint calibers. (sorry for the bad picture)