Both of these guns are very versatile, the 25-06 is a 30-06 necked down to .257 caliber and the 243 is a 308 necked down to .243 caliber. You can use smaller bullets with the 243 and larger ones with the 25-06. The 25-06 has a little more recoil and if you don't handload there's not as many choices of ammo already loaded for it. Having said that there's still at least 30+ loads for the 25-06 but you can easily find 60+ for the 243. 25-06 ammo might be a little more cost wise. The 243 has many loads that are 85grs, 90grs, 95grs, and 100grs loaded that you can use for deer and antelope hunting. They are both great calibers and the 243 has enough energy to humanely and properly take deer and antelope at 300 yards and go really long on coyotes and varmints. Personally i'd go with the 243, I have both but just favor my 243.