Re: 22-250 or 243 700 Yard Woodchuck Caliber
I find myself in the same boat as you. 700 yards is about max shooting for me also. Maybe an occasional 800 yard shot, but mostly 400-600 is the long shots.
I spent alot of time looking at bullets and cartridges before I decided what to build. I went with a standard 22-250 with a 28" 1in8 twist Krieger barrel, on a reworked 700 action with a Manners stock.
I built this rifle to specifically shoot one bullet. The Hornady 75 grain A-Max. And shoot it does. As well as having a much better BC than the 75 grain 243 pills. I stayed with the standard 22-250 and not the AI because IMO 3300-3350 fps is more than fast enough to push the 75 grain pill. You can get it up to 3500 fps with the AI and Swift, but the barrel life is reduced drastically-so 3350 seemed to be the perfect velocity.
I realize the100 grain+ bullets in the 243 have a decent BC also. But for 700 yard shots you just do not need a 100 grain bullet to kill a ground hog. And I detest crawl offs also.
All you really do with the 243 is burn more powder with a heavier, more expensive bullet, with more recoil than the 22-250 to kill a ground hog. Personally I just do not think the243 is necessary. Maybe if you want to extend to 1,000 yards. But if I wanted to extend to 1,000 then I would skip the 243 completely and go to a 6.5mm caliber.
Study the 75 grain A-Max bullet. You will be pleasantly surprised. Tom.