What has better terminal ballistics an m16 or m4?

Answer 1

The m16 has slightly better ballistics, though how to define better ballistics is open to debate. The m16 is not a more accurate rifle then the m4 as they both use the same ammunition and have barrels of the same type and quality. The diffence between the two is in their barrel length.

The longer barrel of the m16 doesn't make it more accurate though. What it does is give the weapon a higher muzzle velocity. This basically gives the round a flatter trajectory, resulting in slightly greater range.

The barrel on an M4 carbine (military) is 14.5 inches. The standard barrel on an M16 (A1,A2) is 20 inches. This increases the terminal ballistics because of the higher muzzle velocity. The 5.56mm round is stable in flight (m16 A2, M4 twist rate is 1/9") but upon contact with a different medium (IE Human tissue) the projectile becomes aerodynamically unstable because of the greater density of tissue over atmosphere. As the projectile become unstable it starts to yaw (twist in a different direction that the rotation axis) because force is now being applied to the side of the projectile it begins to bend, and finally break in half. The two separate pieces of the bullet than slow because of their smaller mass. Since the two (sometimes three) projecticles now travel apart they damage differed organs and tissues. All of this breaking and fragmentation is a function of the velocity of the bullet at the time of impact. So all things being equal (range, target) the bullet fired from an M16 with the 20 inch barrel will impact the target with more speed than a bullet fired from a M4 with a 14.5 inch barrel. Now as ranges become longer, say 500 yards the bullet from the m16 still might fragment, where as the bullet from the M4 will just punch a clean small hole through the target. I should note though that at ranges under 200 yards there is very little if any noticeable difference in terminal effects. That is why the United States Army uses the M4 carbine now, because most combat in Iraq is in built up urban areas the ranges are short and a shorter and handier weapon is most useful. Simply put 4 inches of gun make a huge difference in urban warfare. Since other weapons in the invertory have the ability to inflict damage at longer ranges (say between 200 and 1000 yards) the M4 works just fine.