6mm Creedmoor – How Velocity Changes With Barrel Length

July 20th, 20236mm Creedmoor – How Velocity Changes With Barrel LengthBill Marr, of Rifleshooter.com, conducted a fascinating 6mm Creedmoor cut-down barrel test that revealed how velocity changes with barrel length. Bill Marr started with a 24″ barrel. Proof Research stainless steel barrel mounted on a Howa action. Bill says that this barrel was well-used, having been through over 1800 rounds. The velocities may be different from a barrel of the same length that is brand new. Bill cut the barrel in one-inch increments. Here are the results of the test:24? 20? 16.1? Velocity: 2755 FPS Rifleshooter cut the barrel in one-inch increments from 24? Just over the legal minimum. The MagnetoSpeed V3 Chronograph mounted on an arm attached to stock was used to measure the velocity. The chrono could be adjusted inwards inch by inch as the barrel was shortened. For the 6mm Creedmoor, Bill loaded Hornady ELD Match Bullets over 41.5 grain of Hodgdon’s H4350, with CCI 200 primers, in new Starline Brass. Bill reports that muzzle velocities varied from 2,893 feet per second at 24? Bill reports: “Muzzle velocities ranged from 2,893 ft/sec when 24? This results in a muzzle velocity decrease of 295 feet/second. The muzzle velocity change per inch of barrel ranged from 6 feet/second per inch between 20-19 inches to 63 feet/second per inch between 19-18 inches. The average velocity change per inch was 37.9 feet/second. Bill concludes: “An overall drop of 37.9 feet per second per inch of barrel length is significant and what one would expect with a 6mm cartridge that is fast moving like the Creedmoor. I’m used seeing 6mm Creedmoors that have slightly longer barrels than 24?. However, when combined with a sound suppression system the additional length makes it more difficult to move the rifle quickly. I would suggest using longer barrel lengths whenever possible with this cartridge. It does lose performance at shorter lengths compared to its big brother, the 6.5 Creedmoor. “More Velocity Data for 6mm Creedmoor from 2017 Cut-Down testIf you are curious about 6mm Creedmoor velocity at longer barrel lengths in 2017, Rifleshooter conducted a 6mm Creedmoor cut-down barrel test from 31 inches to 17 inches. The test included bullets ranging from 95 grains up to 110 grains. The Sierra MK 110gr bullet reached a velocity of 31? The Sierra MK 110gr delivered a staggering 3110 fps. Surprisingly, the velocity did not decrease much in the first few inches. Even at 26? The measured velocity of the 110s after a five-inch decrease was 3073 fps. This is a loss of 7.4 feet per inch. With a barrel that is shortened to 20? However, velocity dropped to 2949 fps. This is a significant (161fps) drop. CLICK HERE to see the complete results of that 31?-17 test. Barrel Cutdown Test. Click Here for 31? Click Here for 31? 6mm Creedmoor Barrel Test Report >>Similar Posts Tags: 6CM 6mm Creedmoor 6mm Creedmore Barrel Length Test Bill Barr Creedmoor Velocity test