The Accidental 6mm Creedmoor
June 28, 2017
The 6mm is what I'd call a "gentlemen's rifle." They have more utility than any .22 and are a little easier and more fun to shoot than the 6.5mm. The bullets move faster, and the ballistic coefficient (BC) in the heavier bullets is excellent, so they make for flat- shooting, low- recoiling cartridges. If you find yourself doing a lot of positional or field shooting and want to see where rounds impact, the 6mm is a great place to start.
The most common 6mm is the .243 Winchester, based on the .308 case. Another popular 6mm is the 6XC created by David Tubb for Across the Course matches. It's based on the .22- 250 case. There's the 6x47 Lapua wildcat based on the 6.5x47 Lapua. Finally, we have the 6mm Creedmoor based on the 6.5 Creedmoor.
Of the bunch, no cartridge combines maximum case capacity in a VLD (very low drag) friendly case like the 6mm Creedmoor.
The 6mm Creedmoor, like a lot of life's finer things, was a happy accident. John Snow, an editor for Outdoor Life and a good friend of mine, wandered over to G.A. Precision's booth during the 2008 SHOT Show. Snow had a few questions for George Gardner for an article he was writing about the process of wildcatting cartridges. Snow talked to Hornady in late 2007 about basing a wildcat on the 6.5 Creedmoor and wanted to get Gardner's thoughts.
Gardner liked the idea and thought that it would be a great cartridge for all the reasons the 6.5 Creedmoor is a great cartridge. It gives the shooter maximum case capacity when loaded to magazine length with VLD bullets.
Hornady, Snow and Gardner all worked together on the project. Snow necked the 6.5 Creedmoor down to 6mm, while Gardner helped draw up the dimensions for a reamer and built the rifle for it. It all went down pretty quickly and successfully.
A couple of years later, Gardner found himself in need of a semiautomatic 6mm for a match rifle and didn't like what he saw with the .243 Win. The neck was way too short, so VLD bullets would seat well into the neck/shoulder junction when
loaded. It's not a big deal with new brass, but brass doughnuts form at the junction and create inconsistent neck tension once reloading starts. This can lead to dangerous pressure spikes, so the .243 Win. was never a contender.
The 6mm Creedmoor from the wildcatting project was the perfect fit. VLDs sat in the case inside a magazine with no issues, so Gardner loaded up a bunch and started competing with it. The G.A. Precision team noticed and started asking Gardner for bolt actions chambered in the same cartridge.
No one wanted to keep necking down 6.5 Creedmoor brass, so Gardner called Hornady to ask what it would take to make legit 6mm Creedmoor brass. Turns out, all they needed was a small insert to size the neck correctly and a new headstamp that said "6mm Creedmoor" (it was a little spendy).
Gardner agreed to pay for the headstamp and tooling insert, and asked that they do a run of brass next time they made some 6.5 Creedmoor before they tore everything down. Factory brass has been available ever since.
The 6mm Creedmoor is a great little cartridge that is growing in popularity. Most shooters are handloading, but loaded ammunition is available from a custom ammo house named Copper Creek Cartridge Co. A fella named Josh Lapin owns the company and specializes in producing whatever load you want. Right now he's loading a bunch of 6mm Creedmoor and 6.5 GAP 4S. Lapin is a smart and hard-working guy that does a great job answering questions. He and his products also perform as advertised.
I tested all of Lapin's standard 6mm Creedmoor offerings and found them to be more consistent than most premium match ammunition. Extreme spreads were limited to the teens, and standard deviations ran in the mid single digits. G.A. Precision built the test rifle, and fiveshot groups under ½ MOA were common. The three 6mm Creedmoor loads that Copper Creek carries are: 105- grain Hornady BTHP, 105- grain Berger Hybrid and 115- grain DTAC.
Finding Copper Creek Cartridge Co. was a pleasant surprise, and we look forward to doing business with them in the future. If you have your eye on an exotic cartridge, or want some ammo loaded just for your rifle, their products are worth trying.