While media fairies prone to hysterical reactions tend to place the AR-15 in the same death and destruction category as plutonium bombs, Zika Virus, and John Travolta’s singing in the movie Grease, it’s really just the little brother of another popular rifle design—the .308 AR.
How much littler? Ballistically speaking, you can compare the two as follows. The AR in .308 fires the .308 Winchester cartridge while the AR-15 fires the .223 Remington (or 5.56 mm NATO) round.
To provide an approximate comparison between the two, we need to look no further than my friend Andrew Chamberlain’s world famous Cartridge Comparison Guide. If we look at kinetic energy, which can be loosely defined as the destructive power of a given cartridge, we find the .223 Remington delivers somewhere in the neighborhood of 1,280 foot-pounds of energy. That’s for an “average” 55-grain load moving at 3,240 feet per second. An “average” 150-grain .308 Winchester bullet, with a velocity of 2,850 fps, delivers 2,704 foot-pounds of energy at the muzzle – over twice as much!
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