SMG ROF and firepower in CMBB revisited

[Marlow]

Quite possibly the bench test in question involved mounting the weapon to the bench, not a shooter firing from a supported possition. This tests the basic mechanical accuracy of the weapon, and would be an expected part of an acceptance trial. I suspect this to be the case, since the grouping at 100 m for one long automatic burst would otherwise be very unlikely (for any weapon, let alone an SMG).

[ August 08, 2002, 12:46 PM: Message edited by: Marlow ]

[YankeeDog]

Originally posted by Marlow:

Quite possibly the bench test in question involved mounting the weapon to the bench, not a shooter firing from a supported possition. This tests the basic mechanical accuracy of the weapon, and would be an expected part of an acceptance trial. I suspect this to be the case, since the grouping at 100 m for one long automatic burst would otherwise be very unlikely (for any weapon, let alone an SMG).

Agreed. That full-auto grouping is either by the best SMG gunner in the world, or the weapon is clamped down.

In the circles I travel, 'benching' a weapon means exactly that - zeroing a weapon in on a target, clamping the weapon down onto a small stand so that it cannot move, and then firing off a number of round to test the mechanical accuracy of the weapon, or to adjust the sights. I have never seen the benching results for an actual WWII rifle (Garand, Lee-Enfield, Mauser, etc.) but most decent hunting rifles of similar caliber will shoot groups measuring only 2-3 inches aross at 250m when benched. Heck, my Glock 9mm handgun will shot a group at least as tight as that Soumi at 100m when benched. This doesn't mean I can achieve anything close to that accuracy with the gun, even under ideal conditions.

The point is, bench tests measure only how accurate a gun is in the mechanical sense; they don't measure how easy it is to shoot accurately with a gun, which is an entirely different thing. Here, factors like sights, weighting, recoil, etc. come in to play, especially when you start talking about maintaining any reasonable rate of fire.

Cheers,

YD

[JasonC]

There was not a practical problem carrying additional rifle rounds due to stowage. The solution was simple and widely used - bandoliers worn over the chest. US soldiers used the cloth belts meant for 30 cal MMGs for this; Germans used their disintegrating link belts from their LMGs.

Filling 5 round clips is a trivial operation, time wise, certainly on the scale of tactical combat actions, which typically last tens of minutes up to several hours. In fact the only complaints about the clips in the case of US soldiers was the inability to top off the clip without removing it (which hardly suggests a lack of time for topping off).

Bench fire measures not accuracy of a hand held weapon - even one fired from a rest - but its mechanical ballistics, with the gun held in a vise. It does not realistically measure hand held barrel climb etc. The shot groups of even carbine ammo at 150 yards or more are still much, much larger than rifle groups.

As for SMG fire at 500 yards, you wouldn't hit a blessed thing. Is the bullet still moving? Sure, but that is meaningless. To hit a man with a single bullet at 500 yards you need 1 mil accuracy, about 1/18th of 1 degree of arc.

A 10 round burst would have to be held to less than half a degree of movement over the entire burst, for the bullets fired to do the rest of the trick. Tripod MGs firing 3500 Joule rounds from stable mounts might manage that sort of thing, but you'd never accomplish it with a hand held SMG firing pistol ammo.

As for the idea that men wouldn't fire rifle caliber ammo through wooden wall obstacles because it was supposedly "inefficient", death is much more inefficient than ammo expenditure. Only tiny hit probabilities are needed to justify firing. Casualties in a day's action typically range 10%-20% of those engaged, most of it from artillery, while men carried hundreds of rounds. You could expend thousands per enemy hit.

If an enemy was detected in a wooden building, of course you would fire at that building. Near any windows or spotted loopholes, certainly, wherever movement was spotted. Most of this would be done by MGs, with rifles contributing modestly. But it could not be done by pistol ammo.

The main benefit of rifle caliber ammo was accuracy out to 500 yards, of course. But both penetration and stopping power when something was hit were definite additional advantages of full power rounds. In fact, the M-1 carbine with 1350 Joules of ME was found to lack sufficient power for reliable one-hit stops, and that is 2-3 times the energy of the pistol ammo fired from SMGs. The same consideration led to the M-1 carbine being considered accurate only to about 100-150 yards - but it is dramatically more accurate than an SMG.

Pistol ammo was designed to hit men without any cover at ranges of 25 to 50 yards. It does that just fine. High volume of fire from SMGs can extend the dangerous area to 75 to 100 yards.

[StellarRat]

Originally posted by tero:

Some data on the penetration for Suomi SMG

at 100 meters: 2 mm of iron

at 300 meters: 1.5 mm of iron, 3 inches of pinewood

Wow, that's a weak round.

[Munter]

Originally posted by YankeeDog:

That full-auto grouping is either by the best SMG gunner in the world, or the weapon is clamped down.

Maybe and no.

Here's the original site about Suomi SMG.

http://www.guns.connect.fi/gow/suomi1.html

It was and still is an excellent, stable and robust piece of hardware. Semi-automatic versions are nowadays sold in Finland for $600 and full auto for $420.

M

[ August 09, 2002, 02:06 AM: Message edited by: Munter ]

[Marlow]

Originally posted by Munter:

</font><blockquote>quote:</font><hr />Originally posted by YankeeDog:

That full-auto grouping is either by the best SMG gunner in the world, or the weapon is clamped down.

Maybe and no.

Here's the original site about Suomi SMG.

http://www.guns.connect.fi/gow/suomi1.html

M</font>

[Munter]

Originally posted by Marlow:

Give me a break. Just because the page does not state that the weapon is fixed to the bench, does not mean that it wasn't. I'm not going out on too much of a limb to say that the group for the automatic fire is not possible unless the weapon is secured to the bench. Please relate your experience that tells you otherwise.

OK, I took a closer look on both the Finnish and the English version of the page separately:

In the English version of the page the writer claimes that all 50 shots were fired in a continuous burst.

In the original Finnish version they presume the shots to have been fired in bursts of (maybe) 5 but nothing is mentioned about a sustained burst.

Quoting from http://www.guns.connect.fi/gow/suomikp2.html

TIKKAKOSKI Oy:n esittelykirjasessa

tyydytään lakooniseen mainintaan: "Virallisissa vastaanottokokeiluissa ammuttu taulu. Matka 100 m. 50 laukausta kestotulta; tuelta." Laukaussarjojen kestoa ei ole

muistettu mainita, mutta vuonna 1942 ne olivat yleensä jo yli viisi laukausta per päräys, koska konepistoolia käytettiin tositoimissa kuin taisteluhaulikkoa: Sarjoja

ammuttaessa ei tähtäimiä käytetty lainkaan, ja laukaukset suunnattiin vastustajan vartaloon, eikä päähän, kuten ampumaradalla voitiin tehdä häiriöttömissä

olosuhteissa: Pahvinen taulu kun ei ampunut takaisin..!

Clearly, the translator had made unjustified shortcuts concerning that detail.

"Clamping down" the weapon is however promptly denied. They report having achieved better results with human testshooters and normal supports (my guess = sandbags) than with fixed mounting of the weapon.

Hell, even I can squeeze off 1 inch groups (single shots, magazine rest, no sandbags) at 100 meters aiming through the open sights on my trusty SAKO m92 (7.62x39).

Suomi SMG doesn't even have a recoil worth mentioning so I wouldn't regard the shown result as fabricated. Back in the olden days when we still had some training with those weapons, you could easily control the bursts and place your shots where you wanted by adjusting "the stream of bullets".

M

[ August 09, 2002, 09:25 AM: Message edited by: Munter ]

[Marlow]

Originally posted by Munter:

Suomi SMG doesn't even have a recoil worth mentioning so I wouldn't regard the shown result as fabricated. Back in the olden days when we still had some training with those weapons, you could easily control the bursts and place your shots where you wanted by adjusting "the stream of bullets".

M

Well, if it is truely put forth as not fixed, then it is a fraud. Semiautomatic from a rifle is one thing (I would expect that to be accurate. However, I have fired 9mm SMGs on automatic before. "Low" recoil or not, anyone who could put 50 rounds of automatic fire into a human sized target at 100 yards would be extremely (inhumanly?) good. The shot grouping shown would be impossible.

[YankeeDog]

Originally posted by Munter:

OK, I took a closer look on both the Finnish and the English version of the page separately:

In the English version of the page the writer claimes that all 50 shots were fired in a continuous burst.

In the original Finnish version they presume the shots to have been fired in bursts of (maybe) 5 but nothing is mentioned about a sustained burst.

Clearly, the translator had made unjustified shortcuts concerning that detail.

"Clamping down" the weapon is however promptly denied. They report having achieved better results with human testshooters and normal supports (my guess = sandbags) than with fixed mounting of the weapon.

Hell, even I can squeeze off 1 inch groups (single shots, magazine rest, no sandbags) at 100 meters aiming through the open sights on my trusty SAKO m92 (7.62x39).

Suomi SMG doesn't even have a recoil worth mentioning so I wouldn't regard the shown result as fabricated. Back in the olden days when we still had some training with those weapons, you could easily control the bursts and place your shots where you wanted by adjusting "the stream of bullets".

M

I can believe a very skilled shooter could get those results firing short bursts from a sandbag rest. That's totally different than firing off the whole mag in one pull.

Thanks for the correction of the translation. That's a pretty big error you caught.

Either way, I still stand by my previous point - these kinds of firing range tests, be they from a bench or a sandbag rest, show only how accurate a gun is in the mechanical sense; they say very little about how easy it is to shoot the gun accurately.

Cheers,

YD

[Olle Petersson]

Originally posted by Marlow:

... anyone who could put 50 rounds of automatic fire into a human sized target at 100 yards would be extremely (inhumanly?) good...

Then I'm inhumanly good!

I would have no problem doing it with a kpist m/45B, which do have some recoil and only automatic setting.

The trick is to release the trigger between each shot, so that the effect is the same as if using semi automatic. It's no problem to do so, the grouping will be tight, and it will (by some definition) be "automatic" fire because that's the weapons setting.

Furthermore it will fit within the description of the firing test mentioned above.

(Using burst fire from said weapon I'd have a >30cm spread on a three round burst, shooting standing without support at 25m range.)

Cheers

Olle

[Munter]

On the same website they give instructions on how to eliminate the effect of the recoil.

A skillful submachine gunner can easily control the recoil and keep the gun steady, by keeping the thumb of his trigger hand behind the breech-cap. This thumb must receive whole recoil force. The butt of the gun is not allowed to hit or even touch shoulder of the gunner. Another way to control the recoil is to keep the gun with stiff hands, again without solid contact on the shoulder.

Been there, done that but got no scars!

M

[Marlow]

Originally posted by Munter:

A skillful submachine gunner can easily control the recoil and keep the gun steady, by keeping the thumb of his trigger hand behind the breech-cap. This thumb must receive whole recoil force. The butt of the gun is not allowed to hit or even touch shoulder of the gunner. Another way to control the recoil is to keep the gun with stiff hands, again without solid contact on the shoulder

Might reduce the effect of recoil, but without the butt solidly against the solid shoulder and without a good cheek weld, your accuracy would be greatly reduced. Maybe the basic fundamentals of marksmanship don't apply to Finnish SMGs?

[Andrew H.]

Actually, during the winter war the Finns used their superior woodworking skills to actually construct benches out of materials in the forest; they then clamped their weapons to the benches and used them to great effect against Soviet attacks.

In fact, in one well-known battle (recounted in "Aataaakkin Pannserit Foorvaart"), Finns destroyed an entire Soviet armored battalion by constructed a larger than usual bench and then clamping a Stug to the bench.

[Munter]

The distances where SMG's were used were mostly less than 100 meters. In dense forests even 20-50 meters at max. In that kind of enviroment you have no time to use the sights as instructed, instead of taking aim as with a shotgun and "hosing down" the targets with short bursts while keeping yourself more or less constantly mobile. These weapons were mainly given to the toughest and most cold-blooded soldiers you could find in order to make the most of their effect.

Yet another capture from the page:

Some Finnish writers of war and remembrance novels say they have given too small numbers of Killed In Action enemy soldiers in their books because "nobody can believe my eye-witness' claim that one submachine gunner can slaughter eighty-five enemy soldiers during a skirmish lasting less than thirty minutes"..!

Markmanship as we know it was cultivated by riflemen and snipers.

M

[Marlow]

Originally posted by Munter:

The distances where SMG's were used were mostly less than 100 meters. In dense forests even 20-50 meters at max. In that kind of enviroment you have no time to use the sights as instructed, instead of taking aim as with a shotgun and "hosing down" the targets with short bursts while keeping yourself more or less constantly mobile. These weapons were mainly given to the toughest and most cold-blooded soldiers you could find in order to make the most of their effect.

Exactly. This type of range is what SMGs are intended for. I have not said that SMGs in their proper role are not effective, only that the tight shot group at 100 meters for automatic fire from a SMG is highly unlikely.

[ August 09, 2002, 11:36 AM: Message edited by: Marlow ]

[Munter]

Well, yes.

And while there isn't any mention in the source how the group was actually shot, we'll never know.

Argh, dammit! Now I have to purchase one of those SMG's to try it out myself as it stimulates my scientific personality. Good thing they're not too expensive...

M

[YankeeDog]

Originally posted by Olle Petersson:

Then I'm inhumanly good!

I would have no problem doing it with a kpist m/45B, which do have some recoil and only automatic setting.

The trick is to release the trigger between each shot, so that the effect is the same as if using semi automatic. It's no problem to do so, the grouping will be tight, and it will (by some definition) be "automatic" fire because that's the weapons setting.

Furthermore it will fit within the description of the firing test mentioned above.

(Using burst fire from said weapon I'd have a >30cm spread on a three round burst, shooting standing without support at 25m range.)

Cheers

Olle

I'm not quite sure I understand what you're saying. Let me see if I've got you right.

1) You are firing a kpist m/45b SMG, a weapon that only fires full auto (i.e., no selector switch for a semi-auto and/or burst setting)

2) You are effectively firing semi-auto (i.e, one round per trigger pull) by releasing the trigger quickly.

3) Using this technique, you can get every round on a man-sized target at 100m.

If this is what you meant, this is decent, but not especially amazing marksmanship. This somewhat depends on details (position you were shooting from, ROF, etc.), I am not familar with he specific SMG you were using, but I would say that most trained shooters should be able to achieve this level of accuracy with a decent SMG.

If I understand your second comment correctly, when firing he same weapon:

1) At at target 25m away

2) From a standing postion with no support or bracing.

3) Short bursts of 3 rounds

Your "Spread" was greater than 30cm, meaning that there was a good chance that on any given burst, at least one round would miss a human-sized target entirely.

Again, I am not familiar with the weapon you are shooting, but I think your results show just how much more difficult it is to control a weapon firing bursts than it is firing single shot. a 30cm spread @ 25m = 120cm spread @ 100m, meaning most of the time, you're only going to get one round on a human sized target per burst.

Being a civilian, I have very little experience firing full auto weapons, but your results sound pretty typical to me. If anything, I would guess an experienced shooter should generally be able to get somewhat tighter groupings firing short bursts with an SMG.

I'd be curious to hear from more people with experience shooting automatic weapons about what kind of accuracy a reasoably proficient shooter should be able to achieve firing single shot vs. burst vs. full auto.

Cheers,

YD

[JasonC]

Yeah, 1 foot = 30 cm of spread for just 3 rounds at just 25 meters sounds a lot more like a real SMG full auto shot group. Firing an SMG effectively semi-auto from sandbag rests to get a few inch groups at 100m strikes me as a silly "at peace" stunt. The 30 cm 3-shot group is about 3/4 of 1 degree of arc, incidentally. I would not be surprised if that rose to 1-1.5 degree for a more typical 5-10 round burst.

At 100 meters, that is a spray 6-9 feet across and the bullets have dropped about a foot. So you can easily see why the effective range is about that far. Go out to 200 meters and the spray would be 10-20 feet across and the drop would be around 4 feet (1/2 second flight time). It is pistol ammo.

[Determinant]

That's a great picture up above. It looks like a still from that awesome film 'Starship Troopers', well except for the gold-rim spectacles maybe.

This raises a serious point of order: The Mobile Infantry and the Finnish Army. Are they <gulp> connected in some sense?

Actually my wife surprised me walking out of the cinema with her previously unsuspected tactical acumen: 'Standing in line and firing machine guns at the bugs - it doesn't really work does it?' she said. Ehh I were reet proud.

You kill bugs good Rico!

Toodle pip!

[Tero]

Originally posted by Andrew Hedges:

Actually, during the winter war the Finns used their superior woodworking skills to actually construct benches out of materials in the forest; they then clamped their weapons to the benches and used them to great effect against Soviet attacks.

Seriously: this must be how it was done since the Finnish arty was ammunition starved and the Red Army was impressed enough by the performance of the Suomi SMG they did take up the SMG in a serious way.

In fact, in one well-known battle (recounted in "Aataaakkin Pannserit Foorvaart"),

I never knew it got translated into Flemish !?!

Finns destroyed an entire Soviet armored battalion by constructed a larger than usual bench and then clamping a Stug to the bench.

What is more the Stug was hull down.

[ August 09, 2002, 06:13 PM: Message edited by: tero ]

[Tero]

Originally posted by JasonC:

There was not a practical problem carrying additional rifle rounds due to stowage. The solution was simple and widely used - bandoliers worn over the chest. US soldiers used the cloth belts meant for 30 cal MMGs for this; Germans used their disintegrating link belts from their LMGs.

Can you name any other armies which used them ? The US and the German army were not the benchmark armies of the war which everybody copied.

Filling 5 round clips is a trivial operation, time wise, certainly on the scale of tactical combat actions, which typically last tens of minutes up to several hours.

Agreed. And by that definition even the filling of a SMG magazine is a trivial operation. So a SMG gunner would be able to carry loose ammo in boxes just like a regular rifle men.

In fact the only complaints about the clips in the case of US soldiers was the inability to top off the clip without removing it (which hardly suggests a lack of time for topping off).

No such problems with the SMG magazine. And one noteworthy thing: the Suomi drum magazine (and I expect the PPSh since it was a copy of it) had no problems with the spring because of the way it was constructed. There was no need to count the bullets put in.

Bench fire measures not accuracy of a hand held weapon - even one fired from a rest - but its mechanical ballistics, with the gun held in a vise. It does not realistically measure hand held barrel climb etc.

I'll have to double check that bit. The term used is "bench rest" and is subject to a number of different translations by the author. As indicated the Finnish language site is much more thorough and detailed and there are a number of translation mistakes and short cuts made in the international version.

For example in the Finnish version there is a section about the accuracy rating of the detachable original and replacementg barrels. The barrels were stamped at the factory. Even with the worst match the shot deviation would be less than one inch at 100 meters. And you would know aout it since the stamp in your Suomi SMG did not match the stamp in the replacement barrel (which indicates the direction the fall of shot would shift).

The pictures are from the army acceptance tests which I expected to be more realistic, rigorous and throrough than having it fired from a clammed down position.

Once accepted the Suomi SMG was originally intended to take the role of the SAW in the Finnish platoon organization (in the two regular squads with no LMG/SAW attached). It admittedly lacked the LR accuracy required but it did fulfill the other requirements (accuracy, high ROF). Its best use was learned and perfected in combat conditions.

One noteworthy thing is only the Finnish and the Soviet armies seem to have embraced the SMG and its combat potential in earnest.

The shot groups of even carbine ammo at 150 yards or more are still much, much larger than rifle groups.

What is the intended ROF of the (I assume you refer to the M1) carbine ? IIRC there was a semi-auto and full auto only version.

Also the grouping is not the is intended end result. A kill is.

Having fired during my service both a Suomi and a Mosin Nagant type bolt action rifle IRL myself I can say the recoil from the bolt action (or even a modern assault rifle) is heavier than from the Suomi firing short bursts.

As for SMG fire at 500 yards, you wouldn't hit a blessed thing. Is the bullet still moving? Sure, but that is meaningless.

All the sources I have read say the 9mm round was/is lethal up to 500 meters. Best (practical) range is referred to as being from 50 to (IIRC) 300 meters.

To hit a man with a single bullet at 500 yards you need 1 mil accuracy, about 1/18th of 1 degree of arc.

So all the sniper stories about LR kills are bogus ? The best sniper ever did not use a scope.

A 10 round burst would have to be held to less than half a degree of movement over the entire burst, for the bullets fired to do the rest of the trick. Tripod MGs firing 3500 Joule rounds from stable mounts might manage that sort of thing, but you'd never accomplish it with a hand held SMG firing pistol ammo.

What range are you referring to ?

As for the idea that men wouldn't fire rifle caliber ammo through wooden wall obstacles because it was supposedly "inefficient", death is much more inefficient than ammo expenditure. Only tiny hit probabilities are needed to justify firing. Casualties in a day's action typically range 10%-20% of those engaged, most of it from artillery, while men carried hundreds of rounds. You could expend thousands per enemy hit.

Here is where the army specific TOE's and weaponry come into play. You use the German and the US army as your yardstick, I the Finnish and the Soviet army as mine. Just because the western armies disregarded the SMG does not mean it was worthless.

If an enemy was detected in a wooden building, of course you would fire at that building. Near any windows or spotted loopholes, certainly, wherever movement was spotted. Most of this would be done by MGs, with rifles contributing modestly.

That is my original argument. What is yours ?

But it could not be done by pistol ammo.

Since when could a SMG not pierce glass or windowpane/doorframe strenght wood ? Or thin plank wall ?

The main benefit of rifle caliber ammo was accuracy out to 500 yards, of course. But both penetration and stopping power when something was hit were definite additional advantages of full power rounds. In fact, the M-1 carbine with 1350 Joules of ME was found to lack sufficient power for reliable one-hit stops,

So by that definition even a bolt action Kar98 would not have the necessary stopping power. :confused:

and that is 2-3 times the energy of the pistol ammo fired from SMGs.

So 3 hits from a SMG burst equal 1 rifle shot ?

The same consideration led to the M-1 carbine being considered accurate only to about 100-150 yards - but it is dramatically more accurate than an SMG.

Which SMG's are you talking about ? Which SMG's was it compared to ?

Pistol ammo was designed to hit men without any cover at ranges of 25 to 50 yards. It does that just fine.

The round is still lethal up to 500 meters.

High volume of fire from SMGs can extend the dangerous area to 75 to 100 yards.

Even beyond that.

[K Jonsson]

Originally posted by tero:

Once accepted the Suomi SMG was originally intended to take the role of the SAW in the Finnish platoon organization (in the two regular squads with no LMG/SAW attached).

This is one thing that most ppl seems to agree on. At least those from Finland But should BFC treat finnish SMGs differently? Probably... Lets see if I can make my point clear. If its role was the same as the LMG in other armies the squad would have relied on it more than soldiers in other armies. Things like extra ammo being carried by other members in the squad and always having the best/toughest member using it might be enough to raise the firepower a little. But one thing that definitely should be modeled that will differ from other armies is the probability that the SMG will be lost if one man is hit. I think it should be treated just like the LMG is mow. Any comments from beta testers on this?

/Kristian

[Olle Petersson]

Originally posted by YankeeDog:

Originally posted by Olle Petersson:

Then I'm inhumanly good!

I would have no problem doing it with a kpist m/45B,

I'm not quite sure I understand what you're saying. Let me see if I've got you right. ...

[Michael Dorosh]

Originally posted by tero:

</font><blockquote>quote:</font><hr />

Originally posted by JasonC:

There was not a practical problem carrying additional rifle rounds due to stowage. The solution was simple and widely used - bandoliers worn over the chest. US soldiers used the cloth belts meant for 30 cal MMGs for this; Germans used their disintegrating link belts from their LMGs.

Can you name any other armies which used them ? The US and the German army were not the benchmark armies of the war which everybody copied.

at.</font>

[gunnergoz]

Originally posted by StellarRat:

</font><blockquote>quote:</font><hr />Originally posted by tero:

Some data on the penetration for Suomi SMG

at 100 meters: 2 mm of iron

at 300 meters: 1.5 mm of iron, 3 inches of pinewood

Wow, that's a weak round.</font>