I have a 17SWM, 22's, 22Mag, 220 Swift, 25-05, 6.5x55, 264 WM, 7mm, 7mm Rem Mag, 308 Norma Mag and a 338 WM. Being I have several rifles, I now doing a 6mm-280AI build. I not saying that you build that set up, but I would look at a 6mm in some type of updated case with a faster twist barrel. There a wide range of bullets from 55grs to 115grs. 6mm will work just fine on Deer, Antelope, coyote's, and several other varmints. It should give ranges out to about 1000yds. The long range shooter use this caliber in there shoots. I generally use slower burning powders for my loading so I am going for higher capacity case without having to go to longer bolt. the 700 Long Action (25-06,270,280,30-06 action) serial no. ending with A thru C are good actions, above can be junk. Some of the shorter 6mm cases will work in shorter actions. So the choices are wide open. Hard choices!