M5A1 Canister issue.

[Apocal]

I was playing a recent QB using a pair of M5 lights in support of my infantry company. Opposing me was a mechanized infantry platoon with five or six halftracks in support. Normally this is no problem really, except that the M5s persisted in using canister rounds against the HTs, which had no discernible effect other than killing (quite reliably) their gunners. There were penetrations registered on almost every shot, but didn't knock out or noticeably hinder the operation of the HTs. The easy work-around was using a target command, which would apparently get the M5s to load the correct shell.

But I was wondering if it is possible to have the TacAI "upgrade" it's shot selection if, say, two rounds fail to kill the target? They had plenty of HE on hand, more than they had of canister rounds and did switch when ordered to target, so it wasn't a bug or anything. Just poor choice of shot on the part of the AI.

[Michael Emrys]

Just poor choice of shot on the part of the AI.

I wish I knew what parameters the AI uses to select what kind of round to load. In your case I might have guessed that with targets within a certain range, it goes to canister, but then I've seen mine fire canister at ranges beyond effective. I've also seen it frequently fire canister at single men, when a burst of MG fire would have been more cost effective.

In your case, I might have expected it to choose AP, switching to HE once a penetration had been achieved, and only gone to canister if the squad that had been inside started spilling out.

Michael

[womble]

I did a little bit of testing with canister using the R35 and was deeply underwhelmed by its effect. The AI opens up on infantry with it at about 200m, but even at 50m it wasn't getting much in the way of hits on infantry in the open. That gun's 37mm HE was more effective (and more plentiful). Dunno if the M5 light's round was somehow better.

[akd]

I did a little bit of testing with canister using the R35 and was deeply underwhelmed by its effect. The AI opens up on infantry with it at about 200m, but even at 50m it wasn't getting much in the way of hits on infantry in the open. That gun's 37mm HE was more effective (and more plentiful). Dunno if the M5 light's round was somehow better.

28 balls vs. 122 balls, so yeah, a bit better.

[womble]

Cor, that's some difference! If hit chance is proportional to lead thrown (which does seem to be somewhat borne out by later research) that definitely makes the round better than the L/21 Puteaux's HE.

[Apocal]

Did anyone confirm this?

I'm fairly sure it wasn't just on my end and it was readily reproducible, but if someone else had a different experience, I'd like to know.

[James Crowley]

In a recent H2H game my Stuart fired two rounds of cannister at a heavy armoured car, before loosing LoS. Both were 'hits' and did no apparent damage; had it correctly used AP, the AC would probably have been toast.

[Holien]

, the AC would probably have been toast.

And show it was in the end.

German 20mm is no use against the Stuart!!

The Stuarts could win the scenario by themselves... Canister against my troops in the houses was very effective and they ended up like Swiss Cheese...

[Michael Emrys]

\Canister against my troops in the houses was very effective and they ended up like Swiss Cheese...

I have to wonder about that. I would expect canister balls to be fiercesomely effective in the open, but not to have a lot of penetration against any kind of cover except at near-pointblank range.

Michael

[womble]

In a recent H2H game my Stuart fired two rounds of cannister at a heavy armoured car, before loosing LoS. Both were 'hits' and did no apparent damage; had it correctly used AP, the AC would probably have been toast.

SpoilerAlert!!!

In the Troina campaign first mission there are some German reinforcements which slip over the ridge to reinforce the fighting positions there which include an armoured car [Edit: it's a PSW 233 with an open top and a shorty 75mm]. I spotted them coming and welcomed them with 4 of my 5 Stuarts. When the AC appeared over the brow, 3 Stuarts spotted it. The first one fired AP at it and killed it first shot at about 120m. The other two that saw it, slightly closer, both fired CAN at it, to spectacular visual effect (as the 'pellets' ricocheted of the sloped armour in a nice fan) and the detriment of the AC crewman attempting to exit the destroyed vehicle. The AC still appeared operational at the moment the CAN shooters opened up.

Tanks and TDs shooting at light armour often can't seem to make up their minds whether to shoot AP or HE, but generally it's not critical.

Infantry with 3 HE rifle grenades and 1 AT rifle grenade always (IME) fire off the HEAT grenade in preference to the HE ones, even at infantry targets.

[Holien]

I have to wonder about that. I would expect canister balls to be fiercesomely effective in the open, but not to have a lot of penetration against any kind of cover except at near-pointblank range.

Michael

From my memory they were pretty close. Barrel through the windows at one stage...

Earlier on they were at a distance and I think less effective. The Stuart HE rounds did more damage at a distance against my troops in buildings. Which I guess is a fair cop...

I will watch out for it when I play CMFI next...

[JasonC]

akd - 28 is canister? I get 27 to a shell from my 12 gauge, firing #1 buck. LOL.

[MikeyD]

I don't think your 12 gauge was firing shot the size of golfballs.

[Michael Emrys]

Barrel through the windows at one stage...

Well, that's one way to clear a room.

Michael

PS: I read a book by a guy who commanded M48 tanks in Viet Nam. He described driving up to bunkers so that the muzzle of the cannon was right against the firing slot and shooting. His guess was that the muzzle blast alone in that confined space was enough to do the job.

[JasonC]

A #1 buckshot pellet is 30 caliber, or 7.62mm. So half the size of those 28. But it doesn't require a tank, either. I personally like lighter loads with 16 pellets a shell (2 3/4, not longer magnums) - but that is still enough to send 96 downrange in under 15 seconds.

But thanks for the detail...

[poesel]

PS: I read a book by a guy who commanded M48 tanks in Viet Nam. He described driving up to bunkers so that the muzzle of the cannon was right against the firing slot and shooting. His guess was that the muzzle blast alone in that confined space was enough to do the job.

I always wondered what happened if you shoot a rifle or pistol into a tank barrel. Could that set off the shell? Or would a bullet (or bullets) stick between shell and inner barrel surface? What happens then?

[Michael Emrys]

I always wondered what happened if you shoot a rifle or pistol into a tank barrel. Could that set off the shell? Or would a bullet (or bullets) stick between shell and inner barrel surface? What happens then?

My guess is that you wouldn't want to be anywhere close by. Just in case.

Michael

[JasonC]

poesel71 - bug on a windshield, and precious little, would be my bets. Not that I'd consider it a recommended safety practice or anything, but as tactics go its right up there with meeting a nuclear attack by ducking under a desk...

The round is only going to fire when the powder charge at its base is ignited, and that's at the wrong end.

An HE shell is detonated by a fuze that is affixed to the end of the round that is at least facing the right direction.

(With AP, there isn't anything to denonate, just a thick and heavy metal "bullet", which wouldn't care in the slightest if you shot it repeatedly).

But even on HE, the fuzes are generally spin activated as a safety measure, meaning they have to undergo the giant G forces from being fired to arm themselves. (This is certainly the case with all modern rounds, was 20-25 years ago when I was "in", etc).

Not that you want to bang on one with a hammer repeatedly or anything, but they are not going to go off just because you tap the top of the shell, not before they are fired.

If one actually is fired and you hit it with a bullet, you probably wouldn't set it off. If you did it would still be going 2-3 times the speed of sound downrange and the explosion would all go that way, too.

The charge that fires the round is generally significantly larger than the charge it carries, and the barrel contains and channels that larger charge easily. But it is a slower, controlled burn of that larger powder charge, rather than an instant-onset high explosive detonation. Still, the one place on a tank best suited to contain a large explosion without hurting anything is the firing chamber, because it is built to withstand massive explosions there thousands of times.

Assuming the breech is closed, to be sure. All kinds of nasty things happen if the powder meant to fire the shell ignites with the breech open. An ember in the chamber from a previous shot can do that with a cloth powder bag as on most larger artillery pieces, though not tank guns. (That is why safe firing procedure for such artillery pieces still includes physically swabbing the breech with a wet sponge on a stick, just like in the Napoleonic era...)

FWIW...