User blog comment:7th Body/Call of Duty Realisticness/@comment-1260687-20100602195050

So are the ones we use: M855 5.56x45mm NATO FMJ. Just look at a picture of one, measure out the distance on a "green-tip" to one of your unmarked rounds, and lop half the "green" off with some bolt cutters. I tested it on a 2x4 before I ever carried them like that, and i was knocking out 1/4 inch plugs in the 2x4, clean through. It makes 'em mean.