# How much would static water change the trajectory of a bullet ? **URL:** \ **Category:** Factual Questions\ **Created:** [April 27, 2006, 1:47am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399 "2006-04-27T01:47:15Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Buck\_Rogers](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@Buck\_Rogers](https://boards.straightdope.com/u/Buck_Rogers)\ **Post date:** [April 27, 2006, 1:47am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/1 "2006-04-27T01:47:15Z")
How much would static water change the trajectory of a bullet? Let’s say your shoot a bullet into water that is somewhat static such as a swimming pool with the filter turned off. What percentage would the drag cof slow it down? I am not naming a specific bullet such as a 30-06, .223 or 9mm because I’m just curious of the average percentage. If a bullet would travel 200 yards in the air in perfect conditions and hit the target; then how many yards can it travel under water? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [April 27, 2006, 2:08am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/2 "2006-04-27T02:08:08Z")
> [@Buck Rogers](#): > > If a bullet would travel 200 yards in the air in perfect conditions and hit the target; then how many yards can it travel under water? One or two yards at most, for a typical bullet. Police ballistics labs sometimes use a specially-designed water tank to capture bullets test fired from suspect weapons in order to preserve the markings on the bullet as much as possible for comparison. These tanks are typically 6-8 feet long–not long at all. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 27, 2006, 2:22am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/3 "2006-04-27T02:22:03Z")
Previous thread: [Gun Shot in Water?](http://boards.straightdope.com/sdmb/showthread.php?t=300666&highlight=water+bullet). ---
**Author:** ![Capa84](https://avatars.discourse-cdn.com/v4/letter/c/8edcca/32.png) [@Capa84](https://boards.straightdope.com/u/Capa84)\ **Post date:** [April 27, 2006, 3:23am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/4 "2006-04-27T03:23:14Z")
This was done on Mythbusters…if you are being shot at, and you can get a foot or two underwater, you are basically safe(up to a certain deflection angle) ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 27, 2006, 3:32am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/5 "2006-04-27T03:32:41Z")
**Buck Rogers** : If can get the Discovery Channel on TV, and are still reading this on Wednesday night, 4/26, switch on or set your VCR or Tivo to record Discovery at 1:00 am EDT (technically 4/27, unless you’re on the West Coast). _Mythbusters_ was doing a show about this subject _while you were posting the OP._ It was a revisting of an earlier show that dealt directly with your question. In the original show they fired a number of different weapons (9mm, rifle, shotgun, .50 cal) into a pool to see how far the bullets would travel. (The myth they were trying to bust was the movie legend that by being a few feet underwater you would be safe from a person shooting at you.) The upshot (har!) was that the more powerful the weapon, the _shorter_ the distance travelled by the bullet. The rifle rounds broke into tiny pieces on hitting the water. The 9mm remained intact, but was non-lethal within a few feet. Myth confirmed (as long as the weapon is fired at an angle, and not perpendicular to the surface of the water). On tonight’s show, in response to viewer questions, they actually fired submerged weapons. Contrary to speculation in the other thread linked above, the barrels did not explode (well, the shotgun did, but the others didn’t). And the results were quite similar to the other test. ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [April 27, 2006, 3:35am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/6 "2006-04-27T03:35:43Z")
A lot is going to depend on the construction of the bullet. Does it retain its shape, mushroom, or disintegrate? ---
**Author:** ![Cardinal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cardinal/32/4000_2.png) [@Cardinal](https://boards.straightdope.com/u/Cardinal)\ **Post date:** [April 27, 2006, 4:45am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/7 "2006-04-27T04:45:14Z")
All of which pretty much confirms what I read as a kid: WWII American frogmen working to blow up landing craft obstacles in the Pacific would catch Japanese machine gun bullets in their hands only a few feet under water. The additional travel, and maybe the angle of entry seems to slow the bullets down that much. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [April 27, 2006, 7:42am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/8 "2006-04-27T07:42:38Z")
If the bullets strike at a shallow enough angle, they’ll just skip off. I’m not sure how shallow the angle has to be for this, though. ---
**Author:** ![Critical1](https://avatars.discourse-cdn.com/v4/letter/c/3e96dc/32.png) [@Critical1](https://boards.straightdope.com/u/Critical1)\ **Post date:** [April 27, 2006, 8:12am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/9 "2006-04-27T08:12:03Z")
at sea level water is approx 784 times as dense as air. (I pulled that from a web site, dont quote me) thats kinda like asking why bullets dont go very far when you shoot them into bricks. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [April 27, 2006, 3:47pm UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/10 "2006-04-27T15:47:08Z")
> [@mks57](#): > > A lot is going to depend on the construction of the bullet. Does it retain its shape, mushroom, or disintegrate? Fired into water, most of the \*Mythbusters \* bullets disintegrated into shrapnel. Fired from underwater, the slugs all perfectly retained their shape, but didn’t go very far. Also worth noting, the 9mm auto was effectively turned into a one-shot weapon as the slide didn’t function underwater and the shell did not eject. IIRC, the 9mm slug only traveled about two feet in water. They didn’t delve into it, but I’m assuming the 12-gage shotgun barrel broke because the slug couldn’t push through all the water in the long barrel. ---
**Author:** ![Scumpup](https://avatars.discourse-cdn.com/v4/letter/s/ce73a5/32.png) [@Scumpup](https://boards.straightdope.com/u/Scumpup)\ **Post date:** [April 27, 2006, 3:52pm UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/11 "2006-04-27T15:52:18Z")
This puts claims of scuba divers using Glocksm to defend themselves against sharks in a new light. If it is actually done at all, it would seem that it would have to be at contact range and the weapon function as a single-shot. Frankly, it doesn’t seem like an improvement on the old-fashioned [bangstick.](http://www.bangsticks.com/qanda.html) ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [April 27, 2006, 3:53pm UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/12 "2006-04-27T15:53:56Z")
I always thought that the scene in _Saving Private Ryan_ was unrealistic, but no one agreed with me – 'til now. I mean, if they can be stopped by less than 1 1/2 feet of sand, they gotta be stopped by a couple yards of water. ---
**Author:** ![Gary\_Robson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gary_robson/32/3448_2.png) [@Gary\_Robson](https://boards.straightdope.com/u/Gary_Robson)\ **Post date:** [April 27, 2006, 5:35pm UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/13 "2006-04-27T17:35:10Z")
> [@Gorsnak](#): > > If the bullets strike at a shallow enough angle, they’ll just skip off. I’m not sure how shallow the angle has to be for this, though. Back in my young and stupid days, my buddies and I used to skip bullets off of a big puddle into targets (the outdoor range wasn’t well maintained). We got to the point where we could skip a bullet into the 2nd ring of the target fairly reliably at about 15 yards using cheap .22s. ---
**Author:** ![DanBlather](https://avatars.discourse-cdn.com/v4/letter/d/f4b2a3/32.png) [@DanBlather](https://boards.straightdope.com/u/DanBlather)\ **Post date:** [April 27, 2006, 6:45pm UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/14 "2006-04-27T18:45:39Z")
I missed the shotgun part of MythBusters what happened? ---
**Author:** ![Swede\_Hollow](https://avatars.discourse-cdn.com/v4/letter/s/3bc359/32.png) [@Swede\_Hollow](https://boards.straightdope.com/u/Swede_Hollow)\ **Post date:** [April 28, 2006, 1:58am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/15 "2006-04-28T01:58:14Z")
[This](http://www.theboxotruth.com/) web site tests various rounds against different materials (water, gypsum board, body armor, etc.). They have three “Water Box” links towards the bottom. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 28, 2006, 4:36am UTC](https://boards.straightdope.com/t/how-much-would-static-water-change-the-trajectory-of-a-bullet/354399/16 "2006-04-28T04:36:40Z")
> [@DanBlather](#): > > I missed the shotgun part of MythBusters what happened? It blowed up real good. The barrel ruptured (a gash six or seven inches long opened up), the receiver cracked behind the breech, and the stock cracked. It was a pile of junk after one shot.