You've gotten plenty of good advise already but I'll throw in my 2 cents because I own all 3 calibers mentioned in the original post. Although I'm primarily a bowhunter, my rifle hunting for whitetails was done exclusively with a .243 for nearly 40 years. I only take high percentage shots and I never lost a deer with it. I started my son with a .243 and he, too, was successful for several years. About 6 years ago, I got the single-shot TC Encore bug. I decided to try a different caliber...still one with mild recoil but a little harder hitting in case I decided to go after bigger game after retiring. I did quite a bit of research on ballistics and recoil on various calibers and read a great deal on forums like this one where most guys generally know very well what they are talking about. I bought a .260 standard taper barrel and, shortly after, I got a good deal on a 7mm-08 standard taper barrel. With a SIMS recoil pad on my Encore, the .260 has the same felt recoil as my son's .243 Winchester Model 70 carbine and only a tad more than my old .243 Savage 110. It is one helluva a shooter that dropped a 220 lb. bruiser buck in its tracks two years ago at 100 yds. Most of my shots are under 100 yds. but I wouldn't hesitate to shoot 300 yds. if a needed to with this barrel. The 7mm-08 barrel on the same Encore produces a little more felt recoil than my .260 on the same Encore with 140 gr. factory loads. My .260 barrel shoots flatter and produces tighter groups at 250 yds. than the 7mm-08. For me, that might be because it feels like my .243 when it goes off or it could just be the accuracy of the barrels. My son liked my .260 so well that he switched to a Savage .260 and it, too, is a shooter (1/2" @ 100 yds.) So while both the .260 and 7mm-08 are great calibers, the ballistic coefficient of the .260 is a little better and it typically offers a little less recoil. Of course the recoil depends a lot on the gun. As others have pointed out, .260 factory ammo is less available and expensive. That's its only downside. Remington, Federal, Black Hills, HSM, and Cor-Bon produce factory loads. You handload so you that shouldn't be a concern since I don't see the .260 going away soon and the loading components will be available for a life time. Remington even began offering .260 ammo in its managed recoil ammunition this year and, while I have tried it, it's supposed to produce better knockdown power out to 200 yds. with .243 or less recoil. Whichever caliber you choose, keep the .243 and take it, and the memories that go with it, out in the field with you once in a while.
