Milk jug Ballistics query

[bigalexe]

For various demonstrations I have heard of people using milk jugs full of water, ice, or even jello. I would assume this is done because it is easily penetrated, commonly available, and cheap.

However as I can attest and I'm sure others can to, when shot with various different loads the jug either gets penetrated or explodes. What I am wondering is if anyone can tell me exactly what causes a jug to predictably tend to explode over just being penetrated. I have a theory on what causes it.

What I am assuming is rounds designed to expand explode the jug, such as hollow points. The regular pointed rounds will tend to pass through the jug. However I've also heard that high-powered rifles can cause the jug to explode, and maybe someone knows at what kind of energy level that starts to happen?

If no one knows, maybe its time for a field test?

THERE IS A PURPOSE:
I want to be able to use milk jugs as cheap reactive targets, and don't want to blow them up early with expanding shotgun slugs on the first shot!

 

[JASmith]

Bullet design, including nose shape & jacket thickness, coupled with velocity strongly influence the rate of energy coupling with the target medium. In effect the strength of rupture is a measure of the amount (or rate) of energy deposited while the bullet goes through the jug.

Thus, a 12 ga slug will deposit a LOT more energy than a 22 LR even though they are goind the same velocity because the frontal area of the slug is more than ten times that of the .22 LR.

I've busted enough of these (along with my sons and shooting buddies) with everything from CB caps to deer rifles to know that the jug is, for the most part, a one shot item. The CB Cap and pistol target loads (throiugh 44 & 45) will show some reaction without necessarily exploding. Your follow-up shots, however, need to be either quick or below the first impact because the jug WILL leak!

If you're concerned about the logistics of collecting and filling jugs, smaller plastic bottles work fine too.

You can also buy water bottles and use them directly, but then the cost of the target is about the same as the cost of the round used to bust it!

 

[DrakeGmbH]

I've shot my fair share of water jugs in the back yard. I can't draw a lot of conclusions based on the results I've seen. Here's a summary of some of them:

7.62x54R FMJ - jug splits wide open, flies about six feet straight up, lands about ten feet away, water sprays 10 yards in all directions
.303 British JSP - jug splits wide open and flies about fifteen yards trailing water
12ga 00 buckshot - jug lays open flat, water flies ten yards in all directions
7.62x39 FMJ - jug splits wide open and flies about two meters trailing water
9x19 Luger JHP (Corbon) - jug splits wide open and rolls about six feet, water sprays about ten feet to all sides
.30 Carbine FMJ - jug splits open, rolls back about four feet, water sprays about five feet to all sides
7.62x25 Tokarev FMJ - jug splits wide open, moves only a few feet to the side, water sprays about six feet to the side from the split
.45 ACP FMJ - jug splits wide open, falls over to one side, water shoots about four feet straight up from the split.
.455 Webley LRN - jug stays put, clean entry and exit wounds, small squirt of water about 6" from the point of impact. I thought I missed the damn thing!

The differences seem to be tied primarily to muzzle velocity but there are a great deal of variables that skew the results such as thickness of the plastic, shot placement, temperature, bullet construction and distance. The only cartridges I've shot at a jug and haven't popped it open were .455 Webley (FMJ and LRN), .380 Auto FMJ, 9mm Makarov (FMJ and JHP) and .32 ACP FMJ. Haven't tried .22LR but I expect it will penetrate through and through without cracking the jug open. I expected more violent results from 7.62 Tokarev and 7.63 Mauser, but they were a bit disappointing. 9mm Luger JHP's put on the most impressive show short of .357 and .44 Magnum.

In short I don't rely on them as a demonstration of a cartridge's wounding capability, but just use them as relatively cheap and fun reactive targets.

 

[bigalexe]

Alright thank you, and Drake I like your fully complete descriptions for some reason I was laughing at them.

I guess what I will figure is that they are only going to last for one shot. I am trying to set up a shooting day between Xmas and New Years and wanted some more fun than paper. I was thinking maybe a 30 rd. Magazine in the .223 AR-15 I have access to and seeing who can put the most rounds through a jug before it drains and falls over. Also I've heard that Jello of your favorite color looks very spectacular when it explodes, so I'm probably gonna try some of that.

 

[rcmodel]

That ain't gonna work.
You only get one hit with a .223 unless you are shooting military FMJ at more then 250 yards or so..

Within 100 - 200 yards, the jug will explode the first shot regardless of if it is filled with water or jello.

The phenomena is known as hydraulic pressure or hydrostatic shock.
It happens when the bullet disintegrates or tumbles and dumps all it's energy into the target instantly.
Somethings gotta give when you hit a water jug with any bullet going 3,000 FPS and it blows up inside the jug.

rc

 

[W.E.G.]

Get close.

 

[BADUNAME37]

The phenomenon referred to is hydraulic pressure.

There is a shock wave that extends from the bullet hitting the water and trying to move the water out of the way so fast, the water has nowhere to go but OUTWARDLY - in ALL DIRECTIONS!

Basically the same thing happens when you shoot a woodchuck with a 22-250 HP bullet and vaporize the critter. All that energy has to go somewhere and that somewhere is out the other side, taking a lot of flesh with it!

 

[Sunray]

"...for some reason I was laughing at them..." That's because shooting safe reactive targets is fun. Not much of a mess to clean up either.
"...hydraulic pressure or hydrostatic shock..." Wonderful stuff.

 

[Jim K]

Blowing up milk jugs is a lot of fun, but not a very scientific way to determine bullet performance.

The blowup is caused when the bullet impact tries to displace the liquid in the jug. Since a liquid is incompressible, the displaced liquid needs to go somewhere, and the only way it can do that is to expand the container. If the container is weak, it bursts.

Jim

 

[bigalexe]

Yes I remember reading about hydrostatic shock awhile back.

I should have titled the thread... "Ballistics of milk jugs," I'm not interested in translating the results into what happens to a living body or bullet performance, just what happens to the jug.

 

[rondog]

Soda/beer cans full of water are also very satisfying, and more challenging to hit.

 

[Clipper]

My shooting buddy buys his milk and juices in 1/2 gallon jugs so he accumulates twice as many...We also like to lay 'em end-on, so we have the crossed seams on the bottom for an aiming point, and if you lay 'em label up, you can check POI against POA. The longer bullet path through water will help make 'em build hydraulic pressure and blow up better when hit with marginal loads.

 

[The Gunman]

All the jugs I have shot come apart!
.270 Win, .223 Rem, .357 Mag.

With the 270 I usually can't find an indication of an exit hole. I assume the jug is too busy getting out of the way and isn't there when the bullet leaves or the bullet just comes apart and doesn't leave a hole?

The 22lr puts holes in them and the water leaks out without much indication of a hit. I don't shoot jugs with the 22 anymore!

If you want some challenge to it, try finding the lids after a center mass hit! Or ask your buddy how high it flew.

 

[bluetopper]

I like shooting milk jugs with cast lead 500 S&W Mag reloads from my single shot Handi-Rifle. Sometimes the bottom and little else stays put while large chunks of the jug go 15' in the air. The water just seems to vanish, or sprayed so fine it appears as such.

 

[ChefJeff1]

I get these giant water jugs from work. Actually, they're empty canola jugs that hold about 35#'s of water. Like milk jugs on steroids.

 

[wobble]

Shooting plastic water bottles (I drink the water first, and refill with tap water) turned out to be a big disappointment when using .22LR. There was no reaction at all, other than leaking water. Haven't tried it yet with my .45LC guns.

 

[DeepSouth]

My brother used to like to impress people by sitting a milk jug full of water on top of a concrete block, when he shot the jug the force of expanding water would bust the block........ every time. I could do it with my 450 Marlin if I hit bottom half of the jug.

EDIT:
He was using a 454 Casull

 

[conw]

It's really not humane to shoot milk jugs with rimfire calibers, geez

 

[kanook]

I use my Red Rider so I can watch it leek to death.

And wear I protection, otherwise "you'll shoot your eye out kid"

 

[JASmith]

Shooting plastic water bottles (I drink the water first, and refill with tap water) turned out to be a big disappointment when using .22LR. There was no reaction at all, other than leaking water. Haven't tried it yet with my .45LC guns.

Try shooting end-on. The .22 will penetrate all the way through, but side-on doesn't give much length for energy transfer. You get a bit more when the bullet travels the length of the bottle.

Your 45, especially with semi-wadcutters, will give a more interesting result done this way -- and you'll get better bragging rights for hitting the small part of the bottle!

 

[rcl5445]

I like to line multiples up in a row to catch my rounds. Usually shoot hp's and check the expansion. When we were kids we would hang them in trees and see who could drain them the fastest.

 

[lions]

When we were kids we would hang them in trees and see who could drain them the fastest.

I always enjoyed whiping up on you with my Daisy.