Alexander Arms introduced the 6.5mm Grendel cartridge at the SHOT show in 2004. The idea was to develop a cartridge in an intermediate caliber that outperformed the 5.56x45 round and was effective as far as 800 yards out. It also needed to be chambered in the AR-15 platform, including the double stack magazine configuration. The cartridge has a “necked up” case based on the 6mm PPC benchrest cartridge.
The 6.5mm Grendel is a versatile cartridge, accurate and compatible with the AR-15 platform, allowing for application in a variety of shooting tasks. The cartridge reportedly holds 4 inch groups of 3 shots at 600 yards easily. This level of accuracy makes it a popular cartridge among varmint hunters. The Grendel retains more energy throughout its flight due to the favorable ballistic coefficient of the bullet and the shape and size of the case. Silhouette shooters appreciate this characteristic of the cartridge, as do military users. The cartridge does not require as much powder to generate the amounts of energy found in similar cartridges, which results in less recoil and longer barrel life.
Specific to military and law enforcement markets, Alexander Arms makes an armor piercing cartridge with a tungsten core bullet weighing 125 grains that they claim is capable of penetrating a level III SAPI hard plate at 300 meters. Another valuable characteristic of the Grendel in military and law enforcement applications is the reliable function in rifles with full automatic and three shot burst capability. It is also able to be fired in belt fed weapons if necessary.
Commercially available Grendel ammo bullet weights range between 85 and 130 grains. Muzzle velocities are in the range of 2,500 to 2,800 feet per second, and some loads see the bullet still retain more than 1,000 foot pounds of energy at 600 yards. 6.5mm Grendel ammunition is manufactured by Alexander Arms, Hornady, and Wolf Performance Ammo. This keeps the cartridge easier to find and makes the price point comparable to similar cartridges.