how far can the average bullet pentrate through water?

Question

feet meters etc. list several bullet sizes/ guns.
at a minimum at least the M16 M4 and AK47

Answer 1

http://en.wikipedia.org/wiki/MythBusters_(season_3)#Bulletproof_Water

Answer 2

As Kar already mentioned ricochet is a factor. Your question involves a lot of variables: What kind of .9mm? A subsonic round? A +P? A +P+? A 158 grain submachine gun solid round? If the bullet strikes the water at an angle and ricochets then you are safe but others are possibly in harm's way. Hollowpoints have the best chance of deforming upon striking the water and expending all their energy before reaching you. The solids, especially the ultra powerful 158 grain submachine gun round, have the best chance of reaching down and getting ya. To answer your question, I believe you would have to be at a depth of one fathom to be safe. Relax, a 'fathom' is only: A unit of measure equal to 6 feet (or 1.83 meters). H

Answer 3

three to four feet in the vertical position however as a general rule the faster and lighter the round the less penetration and once you start angling the shot the penetration of the round decreases vastly Mythbusters the tv show did an episode on it most did not penetrate or touch a target 1 foot under water at a distance of approx 5 feet giving you about shot at 35 degrees

Answer 4

If bullets strike the water at a shallow angle, they will ricochet off the surface without any penetration at all.

An old friend and I used to shoot at targets, ricocheting the bullets off the surface of the Conecuh River. And there is, or was, a long range match held at Lake Zurich annually wherein contestants must ricochet bullets off the lake surface to strike their targets. Range in that match is 800 meters, IIRC.

Doc