# Shot gunning from a tank: M1028

The M1028 is a 120mm shotgun shell for the M1 tank. The shell holds 1100 10mm tungsten balls. They are apparently lethal up to 700m (765 yards). Here is a video of the shell being fired in slow motion. It shows the shot breaking the sound barrier and the shot pattern (H/T to Sebastian).

I tried to calculate the weight of each ball. It depends on how pure the balls are. My calculations, based on a company that makes tungsten balls that weigh 18 grams per cm3, indicate that each ball will weigh about 145 grains. That is a combined weight of 159,500 grains / 10 kilograms / 22.8 pounds!

(4/3) x pie x 0.5cm ^ 3 = 0.52 cm3
0.52 * 18 = 9.42 grams (145 grains)

Please correct me if I am wrong.

The requirements of the round were:

• Defeat >50% Advancing Squad w/ 1 Shot
• Defeat >50% Advancing Platoon w/ 2 Shots
• 200-500M (threshold)/100-700M (objective)
• Muzzle Action (i.e. No Fuze)
• No orientation of the projectile
• Vulnerability no worse than current fielded

The M1028 cross section.

Here is a before and after shot taking during the testing of the round. I am not sure of the range.

Before

Two dummies survived, the wall did not.

The concept of shot is not new. Grape shot or loose stones, metal and glass have been used for as long as cannons have.

American Revolution grapeshot

Sources of information:

#### Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.

• I read about shotgun/canister rounds for the British Saladin armoured car a while back. Read somewhere that they were extremely useful for jungle warfare and counter-ambush work but can’t remember the exact source of this info.

• Did you see the concertina wire test in the PDF? It looks like the shell has the opposite effect, as it restores damaged wire to a functional state.

• Roys, thanks for that info, I will hunt around for it.

Haha, Steve, yes I did see that. I think it is a pretty useful feature!

• I’m impressed by the grapeshot, but even more so by the way the high-speed camera can follow the cloud of balls all the way down the range. That’s some impressive target chasing capability.

• Also, I missed Roy’s comment. Some old tankers I know told me that the British [url=http://www.army-guide.com/eng/product903.html]Centurion[/url] also had canister ammunition for its 105mm gun.

Elsewhere, I’ve read that some battleships could fire grapeshot from their 14- to 16-inch main guns — consisting of three- or four-inch balls, intended to discourage torpedo boats or destroyers. Unfortunately a quick Google search hasn’t turned up any examples of these.

• Dave

How did a camera possibly track the shot like that? I’ve spent 6 years in the professional audio/video broadcasting industry, and never heard of anything capable of tracking like that. It’d need a *super* fast servo, and the left to right tracking would have to be predefined, based on a few previous test shots. Anybody know what was used to film? Other option is a special camera, with a *very* wide aperature that filmed the whole thing… all you see is a cut, moving segment of one solid video. Don’t know of anything capable of that either… last option is, CG hoax.

• I remember reading something about the difficultly of recording shot patterns while they are in the air.

Dave, if you figure this out please let us know!

• Nobody

I would like to say, not much.

1. The weight ratio to figure the weight of each ball is not correct. The final production payload weight is not the same as used in calaculations here.

2. Camera? Most of these around here are capable of flight following projectiles at twice the speed of the CAN. Spark graphs measure in the 10 to the -9 range, (1 nanosecond) flight followers can capture at the 10 to the -12 range (1 picosecond). Slowed to human eye capabilities, one can off hand see the pause betwen a hummingbirds wing beat. If one were to be on break or pre-setup that is.

3. Leave it to some powerpoint ranger to place the after shot under the word before, and before under after. Is good help still that hard to come by?

• Hi Nobody, are you able to tell us the correct weights?

My weights were based on a commercially sold tungsten alloy.

(Readers: Nobody hails from a .mil)

• Nobody

Hey Steve, I’m not calling your ratio or equation; I’m calling the data used for the equation incorrect. The data that is widely available on the net and what is final production are not exactly the same. I can say that 10mm is not the actual size per tungsten ball. Additionally, the final production payload weight is different. The final snafu is what keeps our enemies and many times our allies as well, guessing. Did you know the parasitic weight of the aft body and the break away aluminum body is part of the payload weight? It is. The aft body can be clearly observed in the flight follower video. Further investigating on the web may produce another video taken from the muzzle angle. That video shows the break away panels, the dispersion of the payload, and the aft body. Take it however you like, but as a munitions technician, I commend you on a job well done with public release information.

• Frank

We had Beehive rounds for the 105mm and canister for the 152mm during Viet Nam. Both used flechettes (nails with fins). Beehive could be set to detonate at a range or at muzzle. The Cannister could only function at muzzle. Look up ‘Beehive’ and ‘Cannister’ on wikipedia for more details.

• Thanks for the info, Frank

• Nobody

Found this link while conducting OPSEC on the net. Almost, almost!

http://www.janes.com/extracts/extract/jah/jah_5345.html

• Nomen Nescio

i admit i don’t know how the footage was filmed, but i can see how it might have been. you wouldn’t need to track or pan the actual camera; use a rotating mirror instead to bounce the image into the camera lens.

• My understanding is that this sort of large-scale supersonic slow motion can also be done with a carefully synchronized array of ordinary cameras–each camera in the row fires just a few dozen microseconds after the camera before it. Here’s an example:
http://www.digitalair.com/techniques/frozen_moment.html

• Mu

The most interesting fact to me is that the aluminum “pusher”, which shows in the movie, is slowed LESS than the high density balls. Shows how inefficient a shape a round ball is wind resistance wise.

• Lance

Not a surprise its the same as a 90mm Canister round used by US tanks in Korea in the 1950s.

• Al T.

Small quibble… “Two dummies survived” – uh, no, two dummies were left standing. They may have had holes from the round that are not visible in the picture. ðŸ™‚

• chief

I read somewhere that a similar round was used in vietnam by australian centurion tanks to clear thick vegitation like bamboo.

• Evil Pundit

Your reading is correct, Chief. I know some Australian Centurion veterans at a nearby regimental museum, and they have talked about using this round.

• MibZ

When I saw a video of a 2 Gauge being fired and taking out a wall of clay pigeons I never thought I would see a bigger shotgun blast.

I was wrong.

That one took out the wall.

• The shell holds 1100 10mm tungsten balls. They are apparently lethal up to 700m (765 yards).
_____________
Lisa

• Zera

As crude as it is to say, I’m inclined to admit that I call this kind of round “120mm CC.” ‘Closed Casket.’

• Sam Suggs

this concept is ancient. two dummies survived is probly a bit pursumtuiouse