Still, there are times when a .223, regardless of bullet weight, just doesn't cut it. Sometimes you need more power downrange. For example, not long after our special forces hit the ground in Afghanistan they started asking for more .308 rifles that could neutralize distant targets across windy canyons.
The .308 Winchester cartridge, also known as the 7.62mm NATO, fires a bullet three times heavier than that of the .223 with roughly twice the energy. Previous U.S. military weapons that have fired this cartridge include the M-14 rifle and M-60 machine gun. Now Bushmaster, one of the top manufacturers of .223 semi-auto rifles, is producing a .308 based on the ever-familiar AR-15 platform.
Familiar But Different
Outwardly, the new .308 Bushmaster AR-15 looks very much like any of the company's .223 guns, except that the receiver looks stretched to accept a larger magazine. Bushmaster designed its .308 rifles to use FN FAL magazines that hold 20 rounds.
This decision to use a proven magazine that exists in tremendous quantities was a smart marketing move. Other manufacturers of AR-style .308 rifles either use expensive proprietary magazines or require modifications to existing magazines. That adds substantial extra costs. In contrast, the FAL magazines used by the Bushmaster .308 models can be found at just about any gun show, usually for less than $10 each. Both inch and millimeter magazines can be used without modification.
As it does with its .223 guns, Bushmaster machines both the upper and lower receiver from 7075T6 aircraft grade aluminum and then hardcoat anodizes the receivers. Steel parts are coated with a tough manganese phosphate for corrosion resistance. The result is a beautiful rifle with a nice, even finish that's slate gray in color.