Re: 260-6.5x55-6.5x284 experiences
I actively shoot a 6.5x284 using Sierra 142gr MK @ ~2800fps. I've shot several whitetail bucks, close to 10 antelope, 3 texas hogs, a mouflon sheep, and a bunch of coyotes with this load. Ranges from 80 yards to 600 yards. I've shot rocks and paper out to 1100 yards with it and it still holds accurately to that distance. Gun+scope weighs ~10lbs and recoil is not bad at all. The most rounds I've shot in a single day is probably around 70 and never got recoil fatigue (shooting explosives at BoomerShoot). I'm approaching 1000 rounds through my current barrel and haven't seen a drop in accuracy, yet. Obviously all the cartridges you suggest can shoot the same bullets. The 6.5x284 will have the most capacity and therefore more velocity potential, probably erode a barrel faster, a little more recoil and more expensive brass. I've got Norma and Lapua brass both on their sixth loading, so brass life has been good. My load is below max, as some of the competition shooters get 2950-3000 fps out the same pill with 30" barrels, my barrel is 26". If you are really wanting to kill thinner skinned game at 800 yards you may want the extra that the 6.5x284 gives you. Hope some of that info helps.