10.36 x 77 (.408 CheyTac®) Brass Cartridge Cases
The 10.36 x 77 (.408 CT) Brass Cartridge is manufactured on Peterson Cartridge’s new, state-of-the-art case line which uses cutting-edge technology to produce some of the most precise and consistent casings on the market. Peterson Cartridge Co is committed to producing Match-Grade Brass that enables our customers to get more reloads per casing than industry average.
- Case type: Rimless, bottleneck
- Bullet diameter: 10.36 mm (0.408 in)
- Neck diameter: 11.12 mm (0.438 in)
- Shoulder diameter: 15.24 mm (0.600 in)
- Base diameter: 16.18 mm (0.637 in)
- Rim diameter: 16.25 mm (0.640 in)
- Rim thickness: 1.60 mm (0.063 in)
- Case length: 77.21 mm (3.040 in)
- Overall length: 115.50 mm (4.547 in)
- Case capacity: 10.32 cm3 (159.3 gr H2O)
- Rifling twist: 330.2 mm (1 in 13 in)
- Primer type: Large rifle
- Maximum pressure (C.I.P.): 440.00 MPa (63,817 psi)
- Download Caliber Spec Sheet (PDF)
- Download Caliber Print/Drawing (PDF)
10.36 x 77 (.408 CT) Caliber Development
Many of the people familiar with the history of the CheyTac®* name know it has been damaged over the years for a wide variety of reasons. The caliber is a valuable and productive round and deserves to be in service, for the traits it possesses. As of the fourth quarter 2016, Peterson Cartridge has brass cases for guns chambered in both the .408 (10.36 x 77) and the .375 (9.5 x 77). The Peterson cases use NATO designations. The 10.36 x 77 can replace the .408, and 9.5 x 77 replaces the .375.
The story of Peterson Cartridge developing a superior brass casing
As you may know, the larger the caliber the harder it is to make consistent, high quality casings. The .408 (10.36 x 77) and the .375 (9.5 x 77) were no exception. Our tooling development team spent 17 long months and over 1,000 man-hours, and produced 49 different iterations of dies and stems before landing on the best combination to make a casing we believe to be superior to the other casings commonly used in CheyTac® chambered guns.
The goal we set for ourselves was to produce .408 (10.36 x 77) and .375 (9.5 x 77) casings with hardness values throughout the head and sidewalls as close as possible to standard hardness values Lapua uses for their .338 Lapua Mag. Our ballistician has repeatedly gotten as many as 15 reloads from our casings without sticking, neck splits or head separation.