I want to know what caliber has the best characteristics for shooting targets that are slightly underwater.
Please no admonitions about ricohchet(sp?)
Let's assume an angle of incidence of 15 degrees or more from horizontal.

I had a skipper that used an 30.06 for gear protection from sea animals, I saw several shots taken, but no confirmed hits, he said the 06 was the best choice, I have no reason to believe or not believe him.
Any ideas on caliber, bullet weights, velocity.

With all the vast rifle knowlegde on this forum I hope someone can shed some light on the subject.

Please no moral jugdments.

low-tech
What ever caliber you use I would think a round nose or flat point "solid" bullet would be best. When hitting the water I think a spitzer would tend to yaw and veer off course. You could reload these solids for nearly any caliber, but they are available in factory loads for the 45/70 [both jacketed and lead] the 375 H&H, and the 458 Win Mag at most big gunstores.
If you do not have a swimming pool to test loads in get a couple of trash cans and a step ladder. Cut some plywood circles that will fit in the trash can figure a way to change their depth get on the step ladder and shoot straight down into the trash can. Let us know what you discover.
You might also try some "solids" in a 44 Mag revolver.
I think heavy bullets that will not expand or fragment in a fairly large caliber would do best.
Many Many years ago one of my dads friends kept a German 8mm Mauser [chrome plated] on his boat to shoot sharks that they hooked, but the sharks were on the surface when shot.

I know I know but i cant tell . after you do this you will probably need a towel to dry off . please have someone video this so you can get a good laugh afterwards . i do belive a 3006 will go about 12 inches pretty straight in water . i would suggest a 12 ft ladder for this expirement . Bob

by slightly underwater I assume you mean a few inches and not a few feet.

I used to shoot carp in the river and shoot off a bridge. The shots were mostly straight down to 25 degrees from straight down.

I found that AP military stuff for the .308 and .30-06 worked fine but 300 grain Hornady solids worked well from a .375 H&H.

Very few fish was actually hit, they turned belly up and floaded for several minutes due to hydrostatic shock. They then swam away.

If you're shooting two feet deep, it's gonna be a long day. You'll shock a lot of fish but hit very few.

Depending on what your shooting a .22 will go about 12".

The good thing about the .22 is that if your target is close but deeper than that you can just put the barrel in the water and press the barrel against the target or very close to the target and fire. I have seen this with ruger 10-22. The pressure of the .22 rimfire is very low.

I have done this with my rem nylon 66. With the barrel up to the action in water firing semi-auto
blup-blup-blup and water spraying out of the action brings back some memories.

I always used regular 40 grain ammo.

For your question not knowing what your target is I guess I would pick a stainless mini-14 .223 cause the ammo would be cheap and it won't matter what the caliber or bullet is on the water cause they will all end up traveling into the great beyond.

Last year at the FNAWS convention, I attended a seminar put on by Arizona Ammunition . It was very interesting and one topic was round nosed bullets and water penetration. Apparently Arizona Ammo did some developement for an eskimo tribe that needed a man portable rifle (.510 cal.) to finish off harpooned whales. Of all the bullet types and styles that were tried, the round nose solid worked the best. Spitzers and flat nosed bullets all deviated from straight line path in water tank testing. Penetration of the round nose solids were in excess of 12 feet of whale after going through 2 to 3 feet of water.
I would have to guess that the shooting angle used was more than 15 degrees downward.
One question I would have is what type of rifle action do you want? Since salt water is in the picture, figure stainless steel components, so that leaves you with bolt or lever action, (unless you have a chromed Garand or M-14). Bolts can handle the round nose bullets fine, but the lever will not. Faster rounds are not always better.
As far as caliber, .30 and up and bullets that are heavy for caliber, .308" @ 220 grain, .338" @ 300 grain and so on.

According to "How Things Work" it is aerodynamic drag and gravity which brings down a bullet. Also, according to "How Things Work" aerodynamic drag is affected by the density of the medium being travelled through.

So since the gravity doesn't change, and the aerodynamic drag is dependant upon density I think that the bullet travel in water will be equal to the difference in density between air and water.

So the bullet will travel 1/773th the distance in water that it would in air. So if you rifle normally would shoot 3 miles in air it would shoot 20.5 feet in water.

Of course you can research this yourselves at www.howthingswork.com. judy

thanks for all the well thought out responses,

Judy, seems that Hydrodynamics are not my strong suit either.

But seems to me that if air is easily compressed and water is not, the behavior of the medium are not equated.

Don't know, that's why I asked.

You'll have better luck with a bow or a speargun than a firearm.

Digital Dan

The range is too great to use a spear gun, or a bow,

If you're going to test fire anything in a swimming pool, I suggest you try it in someone else's swimming pool. Years ago, I fired a Ruger 10/22 straight down in the deep end (~8') from off the diving board. I jumped in to recover the bullets, and they were flattened. Probably didn't do the plaster pool bottom much good.

H. C.

HenryC470

I agree, do you have a pool?

do you think they flattened on the bottom of the pool, or when or shortly after they hit the water?

low tech, must have been the instant they hit the water since water is incompressible!

<IMPORTANT SAFETY MESSAGE>
Do not dive into swimming pools as water is incompressible you you will be SERIOUSLY injured since the water will not move, again due to it being incompressible!!!!!

You guys truly are clueless, aren't you? judy

[ 09-04-2003, 19:03: Message edited by: Judy ]

Sorry, Judy, but incompressability and fluidity have nothing to do with one another. Liquids are generally said to be "incompressable" (although they actually are, to some small degree). They are, however, just like gasses, a fluid, meaning that they will flow around (or in the case of a pipe or duct, though) a solid object.

I would agree, however, that the flattening of the .22 bullet was caused by its impact with the water and not the bottom of the pool.

sorry Judy, I didn't mean to set you off.

tip toe around this one, hair trigger

Judy,you are correct in a way, those bullets did deform very quickly after hitting the surface of the pool, due to the incompressibility of water. Very Good, you got the right answer, I'm very proud of you.

You seem a little touchy, and ill-informed, that is a bad way to go about life,



I feel a great respect for all your great insights into the physical world.

Rest assured I will hang onto every pearl of wisdom that drops from you tounge, just like in the Political Forum.

Your insight is staggering, and after watching you come up with your calclulation in regards to bullet travel in water, I'm not surprised that other forms of reality are challenging you

Bye

I chose my words carefully, because I don't know for sure. They were CCI Stingers. At the time, I was pretty sure it was hitting the pool bottom that flattened them. I didn't check for chips, and I didn't thoroghly examine the recovered bullets for plaster scuffs. I was more interested in forgetting about the whole experiment and being rid of the evidence. I should have hrown them in a drawer somewhere. I don't think I will be repeating the experiment.

H. C.

HenryC470

I once shot into a 5 gallon plastic bucket filled with water, seems like they were 22lr hollowpoints It cracked the bottom, and sides of the bucket and the bullet was fully mushroomed. It did not penetrate the bottom, and the distance was 1-2 feet of water.

I was living out in the country, and it was a hot day, so the fountain of water felt good.

Recently an experiment was made here and shown in T.V.: Mr. Pablo Sinila of Full Metal fame, shot a special Glock 9 mm. with the arm submerged into the water of a swimming pool. This pistol included a special insert (Glock warns against tryng it with a common gun or in other caliber). Several brands of ammo were used and we saw with some astonishment that even the solids didn�t reach more than 2/3 meters. All bullets were badly bent or otherwise deformed after hitting the water. No harm was made to the pool�s floor.
As explained, this weapon was intended for a Special Operations corp in Cyprus.
Regards

~judy, here are a couple of good links you should check out.

www.lie-aholics.com

and

www.how-to-use-your-brain.com

and

www.TROLLS.Org

You're welcome.

I hate to admit it, but I expected much more from this topic than I got.

gotogirl3

I think I love you!!!!

lotech...sorry 'bout that. Figure out a way to get closer. Firearms are mostly worthless in engaging submerged targets unless they are within inches of the surface, regardless of impact angle. A 15* angle from the horizontal will almost certainly assure a ricochet(no I don't care).

I don't know any of the folks on this thread, but Judy, who seems to get a pretty rough reception, is closer to the answer than most of the other replies are. I are a physicist and the question is one that is actually widely misunderstood. To a first approximation, Judy's answer is correct. For those who want to read more about this, a nice discussion is contained in George Gamow's History of Physics. Gamow was a consultant to the army during ww II and this same question arose with regard to bunker busters. They were puzzled that increasing kinetic energy did not have much effect on depth of penetration. Gamow reminded them of the treatment of the problem of projectile penetration in fluids in Newton's Principia and suddenly it all made sense that increasing kinetic energy didn't have much influence on depth of penetration.

The reply that the way to go is to use a spear gun is also relevant. The closer the projectile approximates a "spear", the deeper the penetration. Also, that 22 sure didn't get flattened hitting the bottom of an 8' swimming pool! Didn't any of you guys waste part of your youth doing these experiments?

When comparing penetration in different fluids, the depth scales as the ratios of the densities.

I found a link to this site from another thread,

http://home.t-online.de/home/nhansen/fundamen.htm

but it looks like if I want to use these bullets I will have to machine them myself.

http://www.nookhill.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=008307

[ 09-11-2003, 03:24: Message edited by: low_tech ]

low_tech, looks like I wasn't so far off with my answer afterall. I guess your handle is appropriate, eh? As I understand it, the supercavitation reduces the DRAG on the bullet; therefore, allowing it to travel further. It also effects the center of pressure, which reduces the bullet's yaw tendency. Like I said all this is pretty well covered in layman's terms at 'How Things Work' judy

[ 09-12-2003, 02:17: Message edited by: Judy ]

Hi Judy,
is that an "I told ya so?"

as I said before I didn't mean to hurt your feelings, and thanks.

as to my handle, it is a testatment to going with what works.

low_tech