The 6.5 Creedmoor feeds just the same as 243/260/308 etc, that is faultlessly. It was developed by Hornady Manufacturing and former US Marine Corps rifle team member Dennis DeMille who is now MD of the Creedmoor Sports target shooting supply outfit that specialises in kit for the US NRA Hi-Power rapid fire / 3-position disciplines. The original remit was a 6.5mm match round to use in AR-10 type semi-auto match rifles and their bolt-action magazine fed equivalents, so fitting in standard AI and McMillan / Tubb magazines with faultless feed and ejection was a must-have feature.
American deerhunters soon saw this match cartridge and demanded factory expanding bullet loads and its use seems to be growing pretty fast in this role. Although the cartridge is only about 8 years old, it's been adopted by Savage, Ruger, Howa, and in Europe Sabatti for its new STR rifle. The big breakthrough especially for us Brits is the new Ruger Precision Rifle offered in 243, 6.5 Creedmoor and 308, another tactical thingie covered in Picatinny rails and looking more at home on a battlefield than on ranges or hills, but very fashionable. Viking Arms can't get enough of them to meet demand, and that's also why it's desperate to get the Peterson ammo and brass, Hornady importer Edgar Brothers not having managed to get its stuff in.