IMO the 260Rem is not an overbore case. The 243Win is closer yet,with more velocity and is not considered a bbl burner.
The 260 is usually used/loaded with heavy for bore sized bullets needing less powder and throat temps are kept somewhat lower. Consider that the 243 can be loaded with 55 and 58gr bullets to well over 4000fps. There is not a bullet made in .264" that can be loaded anywhere near that.
I agree . . . the 260 and the 7-08 are great chamberings,capeable of killing some med to large sized game. --- SAWMAN