>John,
>
>>>Tom,
>>>
>>>Apparently the cartridge tumbles on the M-16 which causes a tremendous amount of damage inside the body.
>>>
>>>
>>
>>An urban legend. The barrel has rifling which gives the bullet a rotational axis, creating more stability in flight. It doesn't tumble, it may wobble a little though.
>
>Thanks for the info.
>
>Then why would the cartridge create more exit damage? Is it the composition of the round?

John is correct in his description of the rifle bullet's path through the air. This tumbling bullet myth comes from people's misunderstanding of the descriptions of wound balistics. The original M-16 fires a 5.56 mm x 45 mm cartridge (.223 Remington) with a bullet weight of 55 grains with a barrel twist rate of 1 turn in 14 inches. This bullet from this rifle does tumble inside the body, leaving a characteristic j-shaped path with a large area of crushed tissue around the curve. Heavier main battle rifle cartridges, like the .30 '06 (7.63 mm x 54 mm, 150 grains) have wound balistics that go straight through the body with less crushed tissue around the bullet path. The AK-47 fires a 7.63 mm x 39 mm cartridge that also "tumbles" because the lead core shifts foreword in bullet jacket on entering the body, causing the center of gravity to shift so the bullet rotates and continues base forward. This leaves a straight wound channel with two large regions of crushed tissue.

The M-16 has gone through a many changes over the years. The current M-16 has a twist rate of 1 turn in 7 inches to stabilize the 62 grain NATO SS109 cartidges (A 1 turn in 9 inches twist is optimal for the 62 grain bullet, but the rifle must also stabilize a heavier, 70 grain light armor piercing bullet.) I have no information on the the wound balistics for the current M-16s.