Case Shot?

I understand this was a projectile similar to what's used in a shot-gun, for use against soft targets. Also called Canister. I'm wondering how much use it saw in WWII, and for which types of guns ( tank guns in particular ) it was issued?

 

case shot

There were pictures posted of these some time ago, I forwarded them to Richard but can't recall which thread.

 

Hmmm...can't speak for WWII, but we carried a round called APERS (or beehive) on our M-60A3 in Korea. You dialed in the ranged and fired. Could be set from 2000m to MA (muzzle action, basically a 105mm shotgun). I was under the impression it was an offshoot of rounds designed for 75mm and 90mm guns used since the Korean war.

 

Wouldn't the range be reduced by a lot? Wait, never mind that....

Why not just hit 'em with an regular shell from twice as far away?

 

Ive read about it being used a good bit in the Pacific war, one of the ways M3 Stuart crews would use it was to defoliate jungle at hidden japanese bunkers, then attack the bunkers with HE rounds.

 

The whole purpose of canister rounds (the usual name for them) was for when you got ambushed and needed something to wipe out hordes of attacking infantry at short range. It had the big advantage that you could fire at your own tanks and clear them of enemy troops without damaging the tanks. Definitely an ammo of last resort, but devastating against packed infantry - much more so than an MG

Tony Williams: Military gun and ammunition website and discussion forum

 

Re: case shot

You mean these?

http://www.fun-online.sk/forum/viewtopic.php?t=3380

 

I witnessed a demo of the 105mm rounds in 1989...100 man sized targets, 1 tank 500 meters away. Shell set for 400m range (to aid dispersal) after the dust settled, no targets standing, and the grass they were in had a swath mowed through it. Nasty round.

 

Don't most tanks use smooth-bore rounds....wouldn't make all that much difference unlike a rifled barrel

 

The older rifled barrels were still able to use canister shot, the projectiles arent fired loose, they travel thru the barrel packed in the "canister", after leaving the barrel the canister breaks apart and the projectiles continue on their way, simliar to a sabot round, where the sabot part of the projectile only serves to guide the projectile thru the barrel, as soon as it exits the sabot seperates, leaving the projectile do its job

 

So either way it doesn't make a difference if the gun is smooth-bore or not. does anyone know how they set the range on the shell? Is it a timer or a fuse type thing or what?

 

A time delayed fuse would ignite a small charge powerful enough to split open the canister after a predeterined flight time. I wonder if rifled barrels were/are a better choice for this type round, seems to me the rotation of the projectile would disperse the "shot" more efficiently also permitting the ability to delay dispersal. Whereas a smoothbore would disperse the shot as soon as it leaves the barrel unless there is a "dispersal charge" to allow the delay, someone else may have a better answer regarding this

 

It's pros and cons I suspect.

From a rifled barrel, the canister would still be spinning up to the point when the canister burst open and the shot were released. At that point, the centrifugal force would fling the shot in a wide pattern, which may actually be doughnut-shaped, with less of a concentration in the middle.

From a smoothbore barrel, the spread would be slower but more even.

Incidentally, the US Army recently started using a modern canister shot, using tungsten-alloy balls, in their 120mm smoothbore tank guns.

Tony Williams: Military gun and ammunition website and discussion forum

 

But with the rifled, would the shot be spining as well? (probably, which means it would spread in a donut pattern.)

 

Err - that's just what I said in my previous post...

Tony Williams: Military gun and ammunition website and discussion forum

 

Why a doughnut shape?

The (offset) radial velocity of each piece of shot is determined by final projectile RPM and the location of that piece of shot within the case prior to it opening (assuming perfect separation of the case). So the pattern, and density of the pattern would be ideally determined by the rate of twist of the rifling and how the shot is packed inside the case.

I don't see how this results in a doughnut.

 

Not quite Tony, I was asking about the revolution of the actual shot not the whole thing.

Each indevidual ball would be flung out at (theoretically) the same rate thus none would remain in the middle. Like a donut....

 

Because if you assume that the shot is evenly packed in the canister, and that this is being rotated at very high RPM (as it will be when fired from any rifled barrel - for a 105mm gun, the typical rate is 25,000 rpm), then only those shot which are exactly in the centre will go straight on. Those are only a small minority of the shot; the rest will fly off sideways to a degree which is determined by the distance from the central axis of the canister. The result tends to be a pattern with a light density in the middle.

This is well understood from attempts to fire shot cartridges from pistols or rifles. They are ineffective except at very short range.

Tony Williams: Military gun and ammunition website and discussion forum

 

All I know is the Stuarts carried them in the pacific, and I know the short German 75s could fire them and also the T-34s 76.2mm could fire them.

I'd think they would be pretty useful in Russia considering the construction on most dachas (spelling?) was purely wood. While bricks might be resistant, I would guess high speed balls would be able to punch through the walls of those buildings pretty easily. At least to me they would seem pretty good shots to clean out buildings.

I'd hardly call it a weapon of last resort though. Within a certain range it would be more effective then HE, especially for the small 37mm like the stuart. I remember reading about a 37mm ATG in the Pacific that managed to halt an attack by the Japs using canister, the dead apperently were in pieces in front of the gun.

 

NM