FANDAMTASTIC round!
As far as I'm concerned, the ONLY reason one would have for buying a 243 instead of 260 is because of availability of ammo OTC. The 120-140 weight range in the 260 is just so much more capable and authoritative than the 85-105 offerings available in the 243. (I'm particularly talking about shooting larger bodied deer. The 243 is fine for deer up to 150#s but the results I've seen on a couple of 200+# bucks my youngest son shot lastyear, left me questioning the 243 and that's with him shooting Barnes TSXs!) A 120-140 Barnes in a 260 AINT stopping inside ANY whitetail...
btw, I fixed "my fears" as my 17 year old now has a 45-70 and my 12yr old has a 7-08.