WWII training film

[Gpig]

Just to wet your whistle for the upcoming WWII CM game . . . interesting stuff. Especially all the actual effects on targets, etc.. Though I was surprised about the effectiveness of the 81mm mortar on the bunker. (Exaggerated?)

http://www.liveleak.com/view?i=a7d_1240819390

Also linked from there is Part 2 of the film.

[John Kettler]

Gpig,

You apparently read minds, for I was going to suggest in your CMSF thread that you cross post this valuable link.

Regards,

John Kettler

[JasonC]

A normal 81mm HE shell wouldn't do that. But there are other kinds...

"The most common was the M43A1 high explosive round, with a weight of 7.05 lbs and containing 1.22 lbs. of TNT. Equipped with a superquick fuze, this round had a bursting radius of about 30 yards was commonly employed against enemy troops in the open. For dug-in or fortified enemy positions, the M56 high explosive round was available. Weighing 10.77 lbs, and with 4.30 lbs. of TNT, this round could be set for impact detonation, or for a short delay to enable it to penetrate before exploding."

50% more round weight, 350% of the standard round's TNT charge, and a fuze delay instead of fuze quick... That gives about the HE load of a 105 shell with delayed. The standard overhead cover needed to stop a 105 direct hit is 2 layers of logs crossways plus 2 feet of sandbags or packed earth. It'd take the same to withstand a M56 direct hit, pretty much (perhaps a bit better penetration before detonation for the 105 round, due to higher flight velocity).

A standard 81mm with quick fuze is meant for frag effect vs. men in the open, is a smaller round with a much smaller bursting charge, and would not hurt a bunker like that...

[sonar]

Thing that struck me, was how fast the bar used up it's ammo. It takes the soldier 7 seconds to use his mag and 12 seconds to reload, this wouldn't be very effective in the fire support role surely?

[JasonC]

Depends entirely on how many people he hits in those 7 seconds.

No automatic weapon can fire continually without exhausting the physical means to move ammunition to the gun. It would take trains, not men. But they don't need to. They only need to hit the men opposite, who are quite as finite as the available ammo supply.

A weapon that fires 1000 to 2000 bullets to hit each man is an effective automatic weapon. Firing opportunities are not scarce; men are scarce.

[sonar]

I was thinking how long he could sustain the fire base if he uses up a mag every seven secs. is the Bar more a close support weapon?

[JasonC]

If you hold the trigger an MG-42 will exhaust a 50 round belt in 3 seconds. The team might carry enough to keep that up for all of half a minute, if an ammo carrier is lugging boxes of the stuff. Every man-carried auto weapon in the war could empty all its ammo in a minute flat.

That is why rate of fire isn't a panacea. The weapon can't make it any easier to carry the ammo, and the damage inflicted is average accuracy times rounds humped, regardless of whether you fire them all in 15 seconds or over 15 minutes. Higher auto fire reduces average accuracy compared to aimed rifle fire or 3 round bursts.

There is only one thing high ROF actually gets you. You can compress more of your total firing time into the periods of peak target exposure, if you are very selective in the use of your shots. What you can't do is just blaze away and pretend that firing faster will mean firing more. It simply won't, it can't. The rate-determiner is ammo humped to the battle location, not weapon ROF.

The strength of auto weapons isn't more overall firing. It is, instead, that fewer men expose themselves delivering the same volume of fire, and therefore present a smaller target to the enemy replies. That, and not any great increase in rounds delivered, accounts for the dominance of auto-equipped infantry over rifle equipped infantry from WW I on.

It is also why that effect is especially marked in a defensive stance. You can't overload it by just sending more men, because sending more men ups your exposure and thus own-side losses (especially to area effect arty). Instead it needs to be defeated by tactics, not numbers. (Mortar vs. direct fire MG, prolonged infiltration, use of the night, etc).

[sonar]

Sorry, I did not mean blasting away like John Wayne. What I'm trying to understand is how long you would expect the Bar to effectively support the squad in combat, wouldn't they run out of ammo pretty quick? Example; squad, as part of Plt. over the course of a couple of hours say, attacks trench line and then beats off a few counter attacks, without resupply how long will the bar remain effective, whats the typical ammo loadout for the bar gunner? This may sound a bit of a "How long is a piece of string" but I hope you see what I'm getting at.

[costard]

It might be that the support is limited more by barrel cooling characteristics and opportunities: I know that even on a rifle range with quite long (relatively speaking) time periods between shots the barrel of a single shot bolt-action rifle can heat up to the point where the dispersion of shot is affected. Of course, a target rifle has a heavy barrel compared to a general issue unit and won't cool as rapidly. Overheated brass can jam in the chamber, overpressured (and thereby deformed) brass can do the same. You can even get rounds "cooking off" if the chamber is too hot - an unexpected unpleasantness and excellent reason for care with where you point a rifle.