You are right about the 260 and 6.5x55. They are excellent deer cartridges and while they are not considered long range deer rifles, they should be. 300 yards is no trick for either of these 6.5 cartridges. While I may get blasted by the 600 yard gang, I consider 300 yards a long range shot at animals and not many hunters can pull off a 300 yard shot consistantly. Just the mechanics involved to make shots past 300 yards hard to pull off on a regular basis. Practice helps but all conditions can not be duplicated to practice effects of wind, elevation and decent range estimation on the part of the hunter. While guiding hunters for many years, not one in ten could make a 300 yard clean kill consistantly.