I heard they have recently made a larger round now for the M-16 in 3.16 caliber(or something like that- I can't remember). But next to the AR-15, the M-16 is considered by most to be the second best assault weapon ever. The only reason the AR-15 is considered the best is because it is almost indestructable, so many are made and they are easy to get parts for, parts easily interchange, they very seldom fail due to dirt and sand, etc.
3.16 caliber would be a bullet 3.16 inches in diameter. and you do know the AR-15 and M16 are the same gun except the AR is the semi-automatic commercial equivalent? saying the m16 is second best to the AR15 is like saying a garand is as good as a garand. i wasn't aware the m16 had such a sterling reputation for holding up in sand and dust. i thought the reverse was more true, requiring more than ordinary care.
