The Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) announced last week they have accepted the new .300 HAM’R (300 HAMR) cartridge.
First introduced by Wilson Combat in 2018, the appeal of the .300 HAM’R was that it could deliver .308 Winchester-ish performance in a necked-up .223 Rem with a 110-to-130 grain bullet that would still fit in a standard AR-15 mag.
Bill Wilson, the father of the cartridge, said the 300 HAM’R was developed for “optimal terminal performance,” with the company saying at its introduction that “Terminal performance testing on over 200 Texas feral hogs has proven it to kill much more effectively than the 6.5 Grendel, 6.8 SPC, 7.62×39 or 300 Blackout.”
The company contends that the round is the most powerful 5.56-based .30-caliber cartridge that can be fired from the AR-15 platform using a standard .223/5.56 bolt.
Since its introduction, Wilson Combat has gone to market with several AR platforms chambered for .300 HAM’R.
As described by SAAMI, the cartridge has a maximum average pressure of 57,500 psi, with a 125-grain bullet traveling at a velocity of 2,450 fps and a 130-grain bullet traveling at a velocity of 2,425 fps.
More data on the .300 HAM’R, here.