I own a Savage model 16 fcss in 6.5 Creedmoor and I love it.
The cartridge itself was designed off the .30 T/C, which is a shortened .308. It has a 30 degree shoulder, and the body has less of a taper compared to .260 or .308. The shortened length of the case is what makes this cartridge excel when it comes to the longer 140+ grain bullets. The shortened case allows these longer bullets to be seated with less intrusion into the case compared to the .260. When you subtract bullet intrusion from the .260's case capacity with these longer bullets, the .260 has a minimal 0.7 grain advantage. When you combine the 30 degree shoulder (20 degree shoulder in .260), reduced body taper, and shorter case length you get a more efficient cartridge that burns less powder and gets the same numbers as the .260. If you reload, that means more bang for your buck. If you don't, the Creedmoor Hornady ammo is less costly compared to the .260. Hornady offers match ammo in 120 and 140 grain A-Max and cost around $26/box. Nosler will start producing ammunition for the 6.5 Creedmoor this spring, as well as brass. One of Nosler's 6.5 Creedmoor loads will be match ammo ($40/box).
The 6.5x284 should be in a long action to make full use of that cartridge. I know nothing of the 6mm Norma BR.
Last edited by Geo_Erudite; January 29, 2013 at 12:28 PM.