6mm Creedmoor: Competition Born and Bred
July 22nd, 2022
6 minute read
Competition breeds innovation, and the story of the 6mm Creedmoor (6 CM) cartridge could be a case study in that regard. If it wasn’t for the Precision Rifle Series (PRS) and the constant search for a competitive edge, it’s likely none of us would be talking about this cartridge.
However, here we are, and I’m going to give you some of the history as well as my thoughts on the cartridge after spending some time with it in a Springfield Armory Waypoint 2020.
The genesis of 6mm Creedmoor is pretty straightforward. Back in 2007, John Snow, a writer for Outdoor Life magazine, wanted to do a story on creating a wildcat cartridge. The plan was to reduce the 6.5 Creedmoor case to 6mm and stuff it with a high BC bullet for better long-range performance. He dubbed this cartridge the 6mm HOLE (Hornady-Outdoor-Life-Express) and after his article was published, it really just became another footnote in the history of wildcats.
[For more information, be sure to read What Is 6.5 Creedmoor?]
A couple of years later, the Precision Rifle Series was starting to gain popularity in the U.S., with multiple long-range matches throughout the year. In these matches, competitors need to engage multiple long-distance targets, usually from alternate positions, under time. George Gardner of GA Precision was using a rifle chambered in .243 Winchester for PRS because it was flat-shooting and low-recoiling. He looked to the 7.62mm AR platform, though, because he could engage multiple targets faster and not break his position to operate a bolt.
The biggest hurdle was that .243 Winchester doesn’t play nice with the 7.62 AR’s magazine. Once you stuff a heavy 6mm bullet into the case, it’s too long for the magazine. That’s when he remembered the 6mm HOLE, which he had a history with because he’d built the rifle for John’s article.
He still had the dies and reamer, so he dusted them off and built himself an AR. The rifle performed beautifully, and soon he was turning heads with top-10 finishes using this new wonder cartridge. People started to take interest. Shortly thereafter, the cartridge was taking off in popularity and it generated enough demand that Hornady began offering it as a standard cartridge in 2017 as the 6mm Creedmoor.
As originally designed, 6 CM starts as a necked down 6.5 Creedmoor case stuffed with 43.2 grains of H4831SC pushing a Hornady 105 AMAX. It retains the 30° shoulder of its parent cartridge which promotes better brass life and the 2.800” overall length means that it will fit any .308-compatible magazine. This adds up to an efficient cartridge that can easily push a 105- to 108-gr. bullet to near 3,000 fps velocities without being overpressured.
Since becoming a standardized cartridge, the number of manufacturers providing off-the-shelf options in a variety of bullet weights has also skyrocketed. It’s not hard to find factory ammo from Hornady, Federal, Remington, Barnes, Berger and Nosler to handle anything from predators and medium game to precision shooting.
The downside to 6 CM is that pushing 6mm bullets to such velocities comes at the price of shorter barrel life. Although barrel life is influenced by several factors, the general consensus is that in a PRS match environment, 1,500 rounds is about all you’re going to get. A shooter may get a slightly longer barrel life if using the rifle for hunting and occasional matches, but don’t expect .308 barrel life from it.
The 6 in Use
Springfield Armory graciously provided me with a Waypoint 2020 rifle in 6 CM for me to use for this article. The ammo scene being what it is right now, I only picked up a box of Hornady Precision Hunter and Hornady Match ammunition from the local gun store. Accuracy for both was very good.
|Bullet||Muzzle Velocity||B.C. (G1)||ES||SD||Best Group|
|108 ELD-M||2,850 fps||.536||.16||6||.75”|
|103 ELD-X||2,872 fps||.512||50||18||.66”|
What does that performance translate to in practical terms? From the perspective of a match shooter, the 108-gr. ELD-M loaded in the Hornady Match is pretty stellar. The 108-gr. ELD-M bullet has a high ballistic coefficient that retains velocity very well at distance and easily cuts through the wind.
Compared to my rifle chambered in .308 Winchester which also has a 20” barrel, the 6 CM needs 30% less elevation out to 1,000 yards and is 25% better in the wind. That bullet also has about 90% of the energy of a 175-gr. SMK at 1,000 yards, roughly 550 lb/ft, on par with a 158-gr. .357 magnum bullet point blank. Looking at the drop chart for my 6.5 CM competition rifle, the Waypoint would be within 3% of elevation and wind dope at 1,000 yards, even though my 6.5 CM has four more inches of barrel.
Although my passion is long-range shooting, I recognize that the 6 CM doesn’t make a half-bad hunting round either. Typically, 1,000 lb/ft of energy is used as the threshold for what would be considered ethical on medium game. The 103-gr. ELD-X bullet in the Precision Hunter ammunition hits that benchmark at about 500 yards. Here on the East Coast where most hunting areas are populated by thick forests, sometimes 100 yards is a long shot. Hornady, Barnes, and Berger have other options with bullet weights from 70 to 100 grains to handle most any varmint or predator also.
Since I had limited ammunition, I wasn’t able to spend a lot of time going beyond 100 yards. I did get in some practice with the Waypoint setting up my tripod and getting into a stable position. My first target was a chest-sized plate at 400 yards with a slight breeze coming from my 2 o’clock. Easy money for the 6 CM, I dialed 1.9 mils on my scope and held just right of center where I easily saw my impact on target. Moving to a similarly sized 480-yard target I dialed 2.5 mils elevation, holding .2 mils right for wind and sent it.
Despite being a sub-10-lb. rifle and shooting off of a front bag, the recoil felt like a .223 and I was able to see my shots impact squarely on target. Whether it was the 108 ELD-M or the 103 ELD-X, both bullets also had practically the same dope, which made switching between the two very easy.
The Waypoint 2020 in 6 CM is a very versatile package that I could carry for a long time and do just about anything with. I think 6 CM’s greatest attribute is opening up the world of higher performing cartridges to shooters that can’t or may not want to hand load their ammunition. Numerous factory rifle and ammunition options make it easier for a shooter to jump into the cartridge and use it for competition or hunting.
However, it’s not a miracle cartridge and 6 CM allows a good shooter to get away with a few more mistakes, but it will not take one from zero to hero. As long as one understands the relative downsides, 6mm Creedmoor bears consideration for PRS/NRL-type events or for a light-recoiling hunting rifle.
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