The Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) just announced approval for three new rifle cartridges, all aimed at sporting use.
.277 SIG Fury
First off, the new .277 SIG Fury, developed by SIG Sauer as the name implies. This cartridge (announced in 2019) fires a 135-grain bullet at 3,000 feet per second from a 16-inch barrel. Maximum pressure is 80,000 psi. SIG Sauer originally developed this round for the US military’s Next Generation Squad Weapon-Rifle, and adapted it for civilian use in the SIG Sauer Cross bolt action rifle. It uses a weirdo hybrid brass/steel case, with steel base attached to a brass case body with a lock washer.
The obvious immediate comparison is the .270 Winchester and its derivatives. The .270 Winchester is derived from the .30-03 military cartridge, and the .277 SIG Fury is derived from the .308 Winchester’s cartridge. Max pressure is far higher for the .277 SIG Fury, but it’s flinging the same weight bullets at roughly the same speeds. Find more details at SAAMI’s website showing the new cartridge’s specifications.
Next up, the 6.8 Western. Olin Winchester developed this cartridge. Because this was developed for hunting, not as a skunk works military project, this cartridge has less information available when compared to the .277 SIG Fury. It pushes a 175-grain bullet along at 2,840 fps. For the sake of comparison, a 6.8 Remington SPC cartridge pushes a much lighter 110-grain bullet at 2,500 fps. Obviously, the 6.8 Western has much more jam for things like elk hunting, and no doubt hunters will be interested.
Finally, the new 6.5 Weatherby Rebated Precision Magnum, developed by Weatherby. The company says it’s based on a reworked Winchester 284 case. This cartridge sends a 140-grain bullet at 3,075 fps, with max average pressure at 65,000 psi. There’s more readily available information on this cartridge, since it’s built on another weirdo case.
The 6.5 WBY RPM, as the company calls it, has a rebated rim, instead of Weatherby’s usual belted magnum with double-radius shoulder. Weatherby did this to enable ultra-high velocity in its Mark V six-lug action. Weatherby says the 6.5 WBY RPM fits into the new Mark 5 Backcountry Ti, which weighs under five pounds. As per the marketeers: “This combination offers maximum downrange performance in the lightest rifle possible.” Welcome news to mountain hunters, then, who are always keen to shed weight from their load, while demanding max hitting power. Find more details on the 6.5 Weatherby Rebated Precision Magnum at the SAAMI specs site. There’s also information at Weatherby’s site, since this cartridge has been out there for a while.