Date: Aug 27 2014
Notes from the Lab: 6.5 Creedmoor
After Hornady introduced the .30 TC cartridge in 2007, it was then necked down to create the 6.5 Creedmoor announced in 2008. It is a truly outstanding target cartridge designed for NRA Highpower and long-range competition, where it quickly earned an outstanding reputation. Factory loads are advertised to push a 120-grain GMX bullet at 3,050 fps, a 129-grain at 2,950 fps or a 140-grain A-Max to 2,710 fps. Recoil and muzzle report are comparatively mild, and with a broad selection of bullet choices, many of which have an unusually high ballistic coefficient, it is also an excellent hunting cartridge.
The parent case is the .308 Winchester. It has had the shoulder moved back with a 30-degree angle, and has an overall cartridge length of 2.800 inches, making it suitable for .308 length actions. Although the Creedmoor case has a slightly reduced powder capacity when compared to the .260 Remington, also based on the .308 Winchester, due to having the small overall cartridge length and 30-degree shoulder, actual useable powder capacity is similar. Its shorter case means bullets can be seated (out) to accommodate different throat lengths and maximize accuracy, while staying within magazine limits. It is efficient, with many of the maximum loads only requiring 38.0 to 45.0 grains of powder. This results in extremely consistent shot-to-shot velocities, and barrel life is expected to be long.
The 6.5 Creedmoor thrives on the same medium to slow burn rate powders as the 30-06, so selection is broad. Ramshot TAC; Norma URP & 203-B; Hodgdon Varget, Superformance & Hybrid 100V; Alliant RL-15 & RL-17; Accurate 2520; IMR-4007ssc & IMR-4350 and several others yielded excellent accuracy. Approach maximum loads with caution, as pressures rose sharply with loads that exceeded the accompanying data.