October 20th, 2017

Tough Brass for Big Ammo — Cheytac Brass from Peterson

Peterson .375 Cartridge Brass Cheytac K02M

Do you have a hankering to shoot Extreme Long Range (ELR)? Then you’ll want a large-caliber cartridge with plenty of boiler room. Some of the most successful ELR cartridges have been based on the CheyTac family, including the .375 CheyTac (9.5×77) and .408 CheyTac (10.36 x 77). Now brass for both these jumbo cartridges is offered by Peterson Catridge. This Peterson Cheytac brass has proven to be tough and long-lived. And it is capable of winning — Derek Rodgers won the 2017 King of 2 Miles (K02M) event shooting a .375 Cheytac with Peterson brass. Here’s a report on how Peterson developed and tested its tough CheyTac cartridge brass.

Developing and Testing CheyTac Brass

Report by Peterson Cartridge Co.
Recently, our president, Derek Peterson, was live-testing our most recent iteration of the .375 CheyTac (aka 9.5 X 77). He started with five casings, and did a full-body resizing after each firing. He got 17 firings out of each before he started to notice the early signs of case head separation. [Editor: Theses were with extremely high pressure loads.] He then took another set of casings and after each firing he just bumped the shoulder back, like a typical reloader would. He got 20 firings out of those casings.

Peterson .375 Cartridge Brass Cheytac K02M
Note: CheyTac® is a registered trademark of CheyTac USA, LLC. Peterson Cartridge has no affiliation.

Low MV Extreme Spread
On the first two shots the muzzle velocities were within 12 feet per second of each other. On the 3rd and 4th shots the muzzle velocities were within 6 feet per second of each other. By the 5th shot the muzzle velocities were within 1 foot per second of each other. Now that is how you can put two bullets in the same hole down range.

No SAAMI Spec for CheyTac Cartridges
As many of you probably already know there is no SAAMI spec on these calibers. So, without a SAAMI spec there is no stated maximum pressure for a service load. However, there IS an international spec on the .408 [promulgated by the] CIP (Commission International Permanente). And the CIP max pressure for this round is extremely high. Our partner in Europe tells us it is probably unnecessarily high. Our partner loads these rounds and they have a standard load for the .375s which is also quite high. So that is the pressure we did our testing at. To even achieve that pressure, we had to use a compressed load. We are explaining all this to say that you [should not use] a load that hot, and therefor you will most likely get more reloads than we did[.]

Peterson Brass Goes Through 11 Dimensional Tests
With all the casings we make in any caliber, we perform a battery of in-process, real-time dimensional checks. [We test] 11 different dimensions continuously throughout each shift. Some of these are tube cylindricity, mouth to body concentricity, primer pocket diameter, length to shoulder, overall length, and more. These measurements are automatically fed into Statistical Process Control software. If a dimension begins to drift from nominal we can catch it immediately and correct it.

Peterson is Fully Committed to CheyTac Brass Production
Peterson Cartridge purchased additional manufacturing equipment designed specifically to produce these large casings. Our capacity is 5-million casings a year. We are committed to there not being a shortage of these calibers ever again.

.375 CheyTac — K02M-Winning, World-Beating Cartridge

Derek Rodgers is the 2017 King of 2 Miles. He is also the only human to ever hit the maximum distance target target at 3368 yards (1.91 miles). His cartridge choice? The .375 CheyTac. Derek ran Cutting Edge Bullets in Peterson brass with Hodgdon H50BMG powder.

Q: Why did you choose the .375 CheyTac cartridge?

Derek: When I was asked to join the Applied Ballistics Team, I needed to get an ELR rifle built in a short period of time. I was under a very tight time schedule to get the project complete. In an effort to eliminate variables, I decided to keep things standard and as simple as possible. I chose the .375 CheyTac for the ease of getting components. The larger rifles are more difficult to get components quickly and I felt like the .375 CheyTac had enough attributes to be competitive at ELR distances.

.375 Cheytac Derek Rodgers KO2M King 2 miles

.375 Cheytac Derek Rodgers KO2M King 2 miles

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