The Sporting Arms and Ammunition Manufacturers’ Institute, Inc., (SAAMI), has announced the acceptance of three (3) new cartridges for SAAMI standardization: 1) 277 SIG FURY; 2) 6.5 Weatherby Rebated Precision Magnum (WBY RPM); 3) 6.8 Western. While the 277 SIG FURY was developed originally for the U.S. Military, it should serve well for hunters, as will the new 6.5 Weatherby RPM and 6.8 Western. SAAMI has standardized the dimensions, max pressures, and load specs for all these three new cartridges.

277 SIG FURY from SIG Sauer

Developed by SIG SAUER for the U.S. Military, the 277 SIG FURY boasts a SAAMI maximum average pressure of 80,000 psi, driving a 135-grain bullet to 3,000+ fps. That 80K PSI pressure is WAY higher than almost all other cartridge types. To achieve these high pressures, the 277 FURY uses a hybrid case with a brass body and harder alloy metal case head. This design allows the cartridge to run very high pressures. Dan Horner of SIG Sauer told us: “When the handloaders get hold of this brass, it will be a game-changer for sure”. We envision this cartridge could be necked down to 6.5 mm and it would dramatically out-perform the 6.5 Creedmoor. And yes the official name of the cartridge is all caps “277 SIG FURY”.

LINK: 277 SIG FURY official SAAMI Cartridge and Chamber Diagram (PDF)

6.5 Weatherby Rebated Precision Magnum

Developed by Weatherby, the 6.5 Weatherby Rebated Precision Magnum (WBY RPM) was introduced with a maximum average pressure of 65,000 psi, with a 140-grain bullet traveling at a velocity of 3,075 fps. The 6.5 WBY RPM offers signficantly higher velocities that most other 6.5mm cartridges, including the 6.5-284 and .265 Win Mag. SEE 6.5 Cartridge Comparison Table

LINK: 6.5 Weatherby RPM official SAAMI Cartridge and Chamber Diagram (PDF)

6.8 Western from Winchester

Developed by Olin Winchester, the 6.8 Western was introduced with a maximum average pressure of 65,000 psi, with a .277-caliber 175-grain bullet traveling at a velocity of 2,840 fps. A shorter variant of the Winchester Short Magnum (WSM) family, the new cartridge appears to be about .090″ shorter than the .270 WSM. It has the same 35-degree shoulder angle as the .270 WSM.

LINK: 6.8 Western official SAAMI Cartridge and Chamber Diagram (PDF)

For additional information on these new cartridge designs and other recently accepted cartridge and chamber designs, visit SAAMI.org.