Well I am an old guy so I better stick to the 6.5x55.The Barnes Manual gives a fair edge to the 6.5x55 over the 260. Most Manuals are the opposite. The Swede in most Manuals is loaded down to respect the many older militatry rifles still being used. In modern rifles of equal strength, the 6.5x55 has the edge.

The 264 bullet performs well on game without the need for blazing speed. The old Swede even at 2500 fps is lethal.. If I were going to build one, I would opt for the 6.5-06. This would give a guy a advantage with the heaviest 264 Bullets.