Designed by Bill Alexander in 2003, the 6.5 Grendel is based on the 7.62X39mm case necked down to take a 6.5mm bullet. Designed for the AR platform, the intent was a military cartridge that would provide greater knockdown power than the 5.56X45mm. As with the several other potential replacements for the 5.56X45, the 6.5 Grendel has not found favor with the military, but with a 123-grain .264-inch bullet at 2610 fps it has a following in the AR community as an accurate and effective medium-range hunting cartridge. Conversion of existing ARs to 6.5 Grendel is a simple matter of swithcing out an upper receiver.
