SAAMI, The Sporting Arms and Ammunition Manufacturers’ Institute, Inc., is the organization at the forefront of promoting firearm safety by creating standards that ensure the safety, reliability, and interchangeability of firearms, ammunition, and components. Recently, SAAMI announced the acceptance of three new rifle cartridges for SAAMI Standardization: 6mm GT, the 6.8 True Velocity Composite, and the 338 Weatherby Rebated Precision Magnum cartridges.
Let’s take a look at these newly accepted cartridges.
The 6mm GT was introduced first by Hornady Manufacturing with a 109-grain bullet that traveled at a velocity of 2,910 fps and a Maximum Average Pressure of 62,000 psi. The 6mm GT was birthed originally between a collaboration with George Gardner (owner of GA Precision) and Tom Jacobs (owner of Vapor Trail Bullets). The GT in the cartridge name is for those two gentlemen, but it also has the nickname of Glorious Tiger, among other names by fans of the round.
From the increased length of the cartridge from the base of the shoulder junction all the way to the increased neck length, the 6mm GT is a longer round than the other 6mm rounds on the market. Those changes allow for the 6mm GT to feed unmodified through a .308-size magazine.
6.8 True Velocity Composite
This round has a revolutionary design with capabilities that could not be achieved by legacy rounds, according to True Velocity. The proprietary True Velocity composite 6.8 case design provides the end-user with significant logistical and operational advantages over metal-hybrid cases or traditional brass cases. These advantages include increased effective range, muzzle energy, reduction in cartridge weight, and enhanced accuracy, just to name a few.
The cartridge was developed in just around eight weeks and exceeds the performance criteria with a 150-grain bullet traveling at a velocity of 2,700 fps and a Maximum Average Pressure of 65,000 psi. The 6.8 Composite cartridge from True Velocity was selected in 2019 by the U.S. Army as a part of their Next Generation Squad Weapon systems.
338 Weatherby Rebated Precision Magnum
The 338 Weatherby Rebated Precision Magnum, or 338 WBY RPM, was introduced by Weatherby and is said to be ideal for backcountry large game. According to Weatherby, this cartridge has been shown to be a good takedown cartridge for elk, bear, and moose. The 225-grain bullet travels at a velocity of 2,800 fps and a Maximum Average Pressure of 65,000 psi.
More information regarding these cartridges can be found on SAAMI’s website, including detailed drawings.