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May 7th, 2019
Our friend Bill Marr of Rifleshooter.com has done it again — conducted a fascinating 6mm Creedmoor barrel cut-down test that reveals how velocity changes with barrel length. This time Bill started with a 24″ Proof Research stainless steel barrel on a Howa action. Bill says this was a well-used barrel, with over 1800 rounds through it. So, the velocities might be a bit different than a new barrel of similar length. Bill cut the barrel down in one-inch increments. Here are some results from the test:
24″ Velocity: 2893 FPS | 20″ Velocity: 2755 FPS | 16.1″ Velocity: 2598 FPS
 For this latest test, Rifleshooter cut the barrel in one-inch increments from 24″ to 16.1″ (just over legal minimum). Velocities were measured with a MagnetoSpeed V3 chronograph mounted on arm attached to the stock. This allowed the chrono to be adjusted inwards as the barrel was cut shorter, inch by inch.
For the 6mm Creedmoor cartridge, Bill loaded Hornady 108gr ELD Match bullets over 41.5 grains of Hodgdon H4350 with CCI 200 primers in new Starline brass.
The results were interesting to say the least. Bill reports: “Muzzle velocities ranged from 2,893 ft/sec at 24″ to 2,598 ft/sec at 16″ for a decrease in muzzle velocity of 295 ft/sec. Muzzle velocity changes per inch of barrel length ranged from 6 ft/sec per inch between 20 and 19 inches to 63 ft/sec per inch between 19 and 18 inches. Average velocity change per inch of barrel length was 37.9 ft/sec.”
Bill concludes: “An average drop of 37.9 ft/sec/inch of barrel is fairly significant and is what would be expected with a fast moving 6mm cartridge like the 6mm Creedmoor. While I’m used to seeing 6mm Creedmoors with slightly longer barrel lengths than 24″, when coupled with a sound suppressor the additional length can make moving the rifle quickly more difficult.
I’d suggest staying with longer barrel lengths wherever possible with this cartridge. At shorter lengths, it does give up more performance than its big brother the 6.5 Creedmoor.”
More 6mm Creedmoor Velocity Data from 2017 Cut-Down Test
If you’re curious about 6mm Creedmoor velocities at longer barrel lengths, back in 2017 Rifleshooter completed a 6mm Creedmoor barrel cut-down test from 31 inches all the way down to 17 inches. The test included four bullet types from 95 grains to 110 grains. With the 110gr Sierra MK, velocity at 31″ was an impressive 3110 fps. Surprisingly the velocity didn’t decrease that much for the first few inches. Even at 26″ (a five-inch reduction), measured velocity with the 110s was 3073 fps, a loss of 7.4 fps per inch on average. With a barrel shortened all the way to 20″ however, velocity had dropped down to 2949 fps, a significant (161 fps) loss. CLICK HERE for complete results from that 31″-17″ Barrel Cut-Down Test.
CLICK HERE for 31″ to 17″ 6mm Creedmoor Barrel Test Report »
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May 7th, 2019
Good Shootin’ Soldier!
U.S. Army SGT Benjamin Cleland recently won the 2019 CMP Cup at the CMP Eastern Games in Camp Butner, North Carolina. And in taking that impressive victory, the USAMU’s Cleland set a new CMP Cup Record of 2389-133X.
The CMP Cup, a 3-day course of fire, includes four stages: 20 standing shots at 200 yards in 22 minutes; two series of sitting/kneeling 10 shots at 200 yards in 60 seconds; two series of 10 prone shots at 300 yards in 70 seconds; and then 20 prone shots at 600 yards in 22 minutes.
Cleland’s new Aggregate Record of 2389-133X beat out his own 2018 CMP Cup record of 2368-111X. What’s even more impressive, Cleland’s score tops the NRA Service Rifle Championship Record of 2386-128X, which the talented SGT Cleland himself set in 2018*.
More Great Performances by USAMU Shooters
SGT Cleland wasn’t the only USAMU hotshot at the Eastern CMP Games. Sgt. Jarrod McGaffic won the CMP Eastern Games’ EIC Match with a 491-21X. SFC Brandon Green won Silver at CMP Cup with a 3-day aggregate of 2385-118X. And SSG Amanda Elsenboss (below) finished as High Woman and 4th Overall in the CMP Eastern Games with a 2378-114X.
The CMP Cup and Eastern Games are shot on Electronic Targets with portable wireless monitors.
* The NRA lists a “Service” record of 2396-181 set in 2009 by SFC Sherri Gallagher. But that was with a Match Rifle. SGT Cleland now holds both the CMP Record and the NRA Record for this Course of Fire with an actual Service Rifle. The USAMU explains: “SFC Gallagher’s record was in a different class, or category: Match Rifle. But since she is military, it may have been labeled as a ‘service record’ and caused confusion. SGT Cleland’s records mentioned above were all in the Service Rifle class, or category. The 2389-133X is the new, 2019 CMP record for this course of fire. In 2018, at the same CMP course of fire, he set a record with his 2368-111X. So he broke his own CMP record this year. However, also in 2018, he set the NRA Rifle Championship record by shooting a 2386-128X. It’s the same course of fire but in an NRA match, so technically, a different “record” since CMP and NRA keep separate records.”
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May 7th, 2019
by Sierra Bullets Ballistic Technician Philip Mahin for Sierra Bullets Blog
A lot of calls that come into the Sierra Customer Service Center are made by shooters [of retirement age]. Most of the time the shooter used to reload back when they were [younger] and stopped in order to raise a family, pursue a career, or both. Maybe their father or grandfather taught them back in the day and they are looking for an answer to the new whatchamacallit they found on the internet. The point is they are coming back to it because it was fun.
Reloading Can Provide Stress Relief
As a father of three, a husband, a brother, a son and son-in-law, and a friend and neighbor, I get pulled in a lot of directions. In all honesty, reloading and shooting has become a stress relief for me even though I work in the shooting industry.
Sometimes, the shooting gets put on hold for other more important things but there will always be another project or repair to accomplish. There are a lot out there that have found a way to balance the work life, the family life, and the play life. I would like to applaud you on your efforts because it is a hard thing to accomplish.
Remember to take time and relieve that stress. Do something fun, especially if it is shooting that special hand-load you just made.
AccurateShooter Comment — Hand-Loading and the Creative Process
Reloading your own precise ammo can be rewarding in many ways. First it allows you a temporary escape from work pressures, “Honey-Dos”, filing your taxes — whatever. It’s just you and Mr. Rockchucker spending quality time in the loading room. Second, hand-loading is a creative process that engages the mind. During load development, you are like an inventor, selecting a powder charge, choosing the bushing size, experimenting with seating depths, working to perfect your load.
Lastly, the process of hand-loading is rewarding because you are building something start to finish. You begin with components — bullets, brass, and powder, and end up with a finished product that (hopefully) is better than the best factory ammo you could buy. It is enormously satisfying to start with piles of bullets and brass and end up with beautiful hand-loads that can deliver great accuracy.
This post originally appeared in the Sierra Bullets Blog.
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