Were infantry guns worth the trouble?

The Germans had them. So did the Japanese and the USA. In caliber they ranged from 70mm up to Germany's 150mm IG33. The concept behind them was to fill the gap between the infantry division's arty and the mortars used by battalions and companies. Generally, they were a regimental/brigade asset. The guns usually were smaller and had less range than normal artillery pieces, running from under 4000yds up to about 9000 for the USA's M3 Howitzer. Here's how I see it:

Assets: 1. Often, quicker response to call for fire than one gets from DIVARTY. 2. Cost less than larger artillery pieces. 3. Less flash/smoke signature (Important for Japanese & German units) than the bigger pieces. 3. Less bulk-more mobile and concealable. 4. More accurate than mortars.

Liabilities: 1. Takes production capacity away from full-size artillery. 2. Generally, not as lethal as DIVARTY guns. 3. Not as portable or concealable as mortars. 4. Not as cheap to make as heavy mortars. 5. Ammunition is more complex than mortar ammo.

I'm not so sure it wouldn't have been better to have channeled the resourses into heavy mortars such as the American 4.2" or the Soviet/German 120mm. What do you think.

 

How do you think of the aspect of direct fire? Try to take out a bunkers loophole with a mortar or try it with light amoured vehicles during they are moving, or urban warfare. And you have the chance to fire AP rounds against tanks. To me they have their place in the Infantery mens world more than a mortar. And the mortars, more the bigger ones aren´t that flexible like a wheeled arty piece. Try to set a heavy mortar quick into a other position while the enemy has sighted you, not a funny job.

 

AFAIK the Germans were planning to completely replace the IG with the 120mm mortar as it had the advantage of being a lot less expensive and lighter so less prone to loss when retreating. For indirect fire purposes a mortar is just as good, secondary direct fire and A/T are an advantage but much better handled by AFVs, IMO the stug was the right solution, it could do direct fire support a lot better than any IG, a stug + mortars for indirect fire combinatrion is superior to any possible IG and in the long run more cost effective as it's more surivable.
To take out fortified positions like bunkers you need a really big gun that can't easily be manhandled, no matter how big is the shield once you have to push it the crew has to expose themselves, engaging an AFV with HEAT from a big low velocity gun is only for emergencies. But then the Germans used the 88mm Flak for bunker busting early in the war, and that was even harder to setup than the SIG 33 so it may not be that big a limitation.
BTW the Italian 47mm was designed as an IG not an AT weapon and the 37mm AT were used as IG in the PTO so the 70mm lower limit is not that accurate.

 

I used to be quite dismissive of the 7,5-cm German light inf gun until a thread on TMP brought up a few details I hadn't considered. It could lay down an impressive concentration of fire (15-20 rpm), engage point targets or indirect ones with high angle fire and outranged the 8-cm mortar of the Inf Bns. Add in to that the points mentioned, that it was organic to the Inf Regts or Bns so cut out the middleman in requesting support fire, and I can begin to see why the Germans tuck with them so long.

The 'cons' to me are the resources needed to keep an Inf Gun Coy functioning in terms of men and horses (approx 200 men and 70 some horses depending on the KStN), and the fact that these guns cannot be tied into the Div Arty Regt proper. British formations never ascribed to guns with the Inf, they concentrated their weapons in Div Arty and from there they could all be directed on a single shoot if required. Those two dozen Inf Guns don't have the range to do likewise for a German Div. The fact that later in the war the Germans looked to use 12-cm mortar as Regt weapons and 7,5-cm guns as Bn ones, in the Volks Grenadier Div, I think perhaps reflects the thinking that the heavier mortars becoming available were a better option.

In the late 1930s having a gun that could be used in point fire, indirect fire, probably also was touted as having an anti-tank capability, was crewed by the Inf it was supporting, could outrange most medium mortars and was reasonably easy to transport and emplace, it probably sounded a very useful piece to have around. Once mortar ranges increase and larger calibre tubes appear, the number of tanks that can be engaged effectively rapidly diminishes, and you move from mobile war to largely defensive operations where 'shoot and scoot' becomes more important, I think the sheen comes off.

The Japanese I think present a different set of pros and cons, given the theatres they operated in and more general limitations on their artillery support.

Gary

 

TOS, you´ve the best solution with mentioning the Stug´s. But to keep a bunker crew down as long as the infantery can eliminate them with some EOD´s or flamethrowers, a light field gun or a 75mm AT gun is worth a lot, and if there is no Stug in a urban place i would prefer the the light arty for the possibility of a direct fire over any mortar.

 

Ulrich,

You're correct that for hitting point targets, either by direct or indirect fire, the gun is better than the mortar. However, your comment re the trouble to set up a heavy mortar is off I believe. The Soviet/German 12cm mortar came on a wheeled trailer that could be easily set up and taken down. The USA's 4.2" (105mm) mortar was manned by the Chemical Weapons Branch and was mounted in half-tracks I believe. I should have also mentioned that the mortar would have a higher rate of fire than an artillery piece.

 

Ask the Marine's who fought in the Pacific how much they loved the 75mm pack howitzer. Easier to move in the jungle environment, and a handy punch against the bunkers and lighter Japanese armor.

 

Thanks Harold,

the German mortars 15cm Gr.W.43 was set up on a steelplate and not easy to move for it crew. Other the Gr.W.69 with 21cm it was a wheeled one and relative handy for its 2 tons of weight. The main weapon for the Wehrmacht mortars was the 8cm Gr.W.42. Can you imagin how hard and unsfe it can be to fire a mortar in woodland or direct in a jungle? You need free space to prevent that the round will explode on the trees above you and is more dangerous to you than the enemy. The smaller guns like the old 75mm leIG18 or the 4,2cm leiPak 41were to handle by its crews, easy to move and you have the chance to blow fortified MG or gun settings away. I can see advantages in indirect fire against bigger infantery units or hidden units in towns before you´re moving in them for the mortars but i´m sure troops with only having mortars weren´t that effective.

 

The US Army 4.2-inch Mortar Battalions were separate units (non-Divisional), but they did not have halftracks. Their weapons were transported primarily by Jeeps and trailers, and over rough terrain by the crews themselves, with the mortar broken down into constituent parts.

 

Some flawed premises and some very confusing and some just plain bad information here.

You're making assumptions that aren't supported by facts. In the German army the infantry gun was to give organic artillery to certain infantry regiments. It was not necessarily to bridge the gap between mortars and artillery. The US 81mm mortar has a range of 3000m compared to the German 7.5cm le IG 18 with a range of 3400 meters, not much of a difference. The difference in the German army was that the infantry gun in the German army was manned by infantrymen and not artillerymen. In the US Marine Corps the M1/M1a1 pack howitzer were actually battalions within the divisional artillery regiment.

The M1 and M1a1 pack howitzer were the versions of the pack howitzer that "might" fall under the heading of infantry gun, the M2 and M3 were vehicle mountings of the same gun, like in the M8/M8a1 HMC, which was a self-propelled artillery piece. It would be a stretch to call it an infantry gun.

It all depends on how the divisional assets are assigned. If for instance an artillery battery were assigned to support a specific unit and the infantry gun were firing in indirect fire mode, there would be no difference. As I stated earlier the reason for the Infantry gun in German service was to give dedicated/organic support. A not uncommon tactic of American employment would be at times they would chop a battery from the artillery regiment and assign it in direct support of a RCT and you have same/same.

Not true. Properly served mortars are just as accurate as artillery.

Again untrue, as stated earlier the M1 75mm pack howitzer was an American field artillery piece. The lethality of the gun is not a characteristic of the gun but of the round fired, a 75mm round fired out of 7.5cm le IG 18 is no less lethal than the 75mm round fired from an German divisional artillery piece such as the FK16nA, FK18, FK38 or FK7M85. The difference is that divisional artillery, would also have larger caliber pieces as well.

Very good and accurate assessment TOS.

Have to nit pick here. The 37mm was an anti-tank gun that was also used to provide direct fire support against fortifications and had a very effective cannister round for anti-personnel use. (BTW, the 105mm artillery piece also had a very good cannister round and was used in direct fire mode to stop the big Japanese banzi charge on Saipan but that doesn't make it an infantry gun). The same gun mounted in the Stuart tank was used for the same purposes but that doesn't make the Stuart an infantry support tank like the M4 105mm.

Now this is an accurate advantage and one of the major reasons the Japanese used Infantry Guns.

You have the same problem firing artillery in the indirect fire mode Ulrich, you'd also be surprised at how small an opening in the overhead you need to safely fire a mortar.

 

USMCPrice,

I'm not sure I agree with some of the things you wrote. Let me explain.

First, DivArty is a divisional asset while the 80/81mm mortars were intrinsic to a battalion or lower formations. The IGs were a regimental asset and something that the Regimental commander could use to influence the battle. So therefore, they were there to bridge the gap in coverage and give the regiment its own indirect (sometimes direct) fire support. Supposedly, a Bn of artillery was to support each infantry regiment but I can tell you from experience that not all requests for divarty fire are honored and many times it takes forever to get the firemission approved. So I think we are saying the same thing, just in a different way. I was thinking organizationally. By the way, Ian Hogg considers the M3 an infantry gun so I'll go with him. It was fired by the cannon companies which were infantry men. Later in the war these were disbanded due to the need to put infantrymen into the line.

Most of the IGs made were around 75mm in caliber. Most divisional arty in the German and American forces started at 105mm. Even the British 25 Pounder (roughly 88mm) was larger. Usually, the larger the round, the more lethal it is. The Germans had the 150mm IG33 which had a large projectile but a very limited range.

Fin-stabilized mortars are NOT more accurate than rifled cannon. I totally disagree with you here. Even the American 4.2" mortar (rifled) was less accurate due to its being fired in a high trajectory, which in and of itself is a less accurate way of firing.

As far as the 37mm gun being an AT gun or a IG is probably contingent on what it's being used for. If it was fired by the infantry and use to support them, then it's an infantry gun. After all the famous 88mm cannon was designed as an AA gun but was used as an AT gun and also as indirect artillery. So, I guess I'll have to say this weapon was an exception to what I wrote in my original post, which is generally correct.

 

mortars and artillery accounted for most of the battle casualties in world war 2. you might ask whether or not rifles, sub-guns and pistols were worth the trouble, considering they accounted for only 5% or casualties (and inefficiently, soldiers fired on the average more than 500 rounds just to kill another soldier.)

 

Hi Mac!

Could you tell me where you got the "5%" figure in your post? It seems a little low to me.

 

I can see the value of weapons like the 75mm le IG 18 during WW2. They were relatively small, easily handled and easily concealed. They gave an Infantry unit a very handy increase in firepower.
In an advance they could be moved up by vehicle/horse or hand to deal with strongpoints and support the advancing units with very quickly available firepower (1939 still had many units reliant on field phones or messengers, no radios to call in quick support). In defence they could be sited to give more accurate direct fire support. Many nations used weapons is this role although quite a few had a secondary (occasionally primary) role of Infantry AT gun.

Germany got rid of its light mortars (until they were issued along with captured weapons to the Volksturm in lieu of artillery), but kept its medium mortars and IG guns.

You still have the same idea of weaponry in service today with the modification of AT rockets to have anti structure warheads, thus giving the infantry their own IG support so to speak.

As a little note you keep confusing me when reading (i have to read a few times to put into context) about Battalions and Regiments as in the British Army they can mean the same thing (old traditions and all that). So in this context are you using Regiment as equalling 3 Battalions (I know some German Regt's went down to 2 Battalions)

 

Hi USMCPrice,

you´re propably right on this depending on the angle it shoots, the free space is very small. I never fired a mortar and we need it most to illuminate the battkefield for night fights. So my experience is very small on it. Thanks for the hint!

 

Ulrich, when I first joined the Marine Corps I went to infantry school and trained as a machine gunner and we were familiarized with the other intrinsic weapons in an infantry battalion. When I checked into my first unit in the fleet, they were way over T/O strength in machine gunners and really short on mortarmen. I got assigned to a mortar crew, was OJT'd as a mortarman and spent like six to eight months doing that before I went to my actual MOS. I became pretty proficient in that job, and put a lot of rounds down range, so I am very familiar with mortars. When I came off active duty the nearest reserve unit was a 155 artillery battery, and I spent maybe three years there, so I'm also pretty familiar with the organiztion, employment, and capabilities of artillery. You and I are buds and I wouldn't blow smoke up your posterior I just wanted to clarify that the scenario you gave is an issue for either type weapon.

 

I am well aware of this that's why I wrote:

This is where I think you're getting off track:

It's not so much to bridge a gap in support, as to address an actual lack of artillery support, a doctrinal shortcoming or a lack of logistical assets in the particular unit. (they lack the logistical assets to support a full fledged artillery component)
If we're discussing US artillery that was plentiful and effective, it was common practice to attach a firing battery to an RCT to provide dedicated fire support (usually 75mm or 105mm) and the 155 batteries were normally retained by the artillery regiment in general support. Except for the period when there was a general lack of artillery ammunition because of a Congressional screw up, infantry units usually got the support they requested when it was requested. It was also common practice for artillery battalions FO's to be attached to the RCT they were supporting, and to have arranged for pre-registered fires so that rounds could be placed on target very quickly. If you are artillery poor, or lack the ability to support an artillery unit then an infantry gun is a good option.

Am I to take this to mean that you actually called for fire support in WWII? If you're talking more contemporary experience I'd have to say that that's not been my experience.

O.K. on this one we may be miscommunicating. You wrote:

and

The US had at least three M3's you could be speaking of the M3 vehicle mounted version of the M1/M1a1 75mm pack howitzer with a range of @8800 yards. The 37mm Gun M3, which was an anti-tank gun that was often used for direct support and the 105mm M3, a shortened 105mm on a modified pack howitzer carriage, with a range of 8000yards. The last was primarily used in the Divisional artillery of Airborne units (1 x 105mm battery and 3 x 75mm batteries). It also saw use in cannon companies of some infantry regiments. You never specified which and I assumed it was either the 75mm or 105mm versions. Because of the specified range and the fact that you stated they were "less lethal" I was thinking pack howitzer but now think you were talking 105mm howitzer.

I don't believe I ever said "more accurate" I said "Properly served mortars are just as accurate as artillery" and I'll stand by my statement. Being "fin-stabalized" is not a disadvantage because of the high-trajectory, relatively low velocity round.

No, it is a function of the weapons intended role and it's place within a units organizational setup. Just because it was common for US forces to at times use their tracked tank-destroyers, such as the M10, as ad-hoc artillery pieces does not make them self-propelled artillery.

 

Hey my friend,

it is always a pleasure to get a advice from a well experienced bud who knows about the facts. ...smoke up my posterior...LOL !
The only experience i made with our arty guys was that they had some troubles in range estimating and shot a round to short which gave me, to my luck, only a few days of a mad whistling noise in my ears. We decided it is much safer to do our urban job without our "Thunderboys".

 

UMCP,

Some of this I believe is splitting hairs. Let me give you some personal background. In the 70s I was trained as an infantryman and then switched branches to artillery so I have some experience with mortars and a bunch with artillery. Certainly I didn't call in fire in WWII unless there is reincarnation so I think this was perhaps a cheap shot. I do know of and have heard/read many accounts of artillery used in WW2, Korea and Vietnam and I have my own experiences as well. All of this boils down to the fact that while often, especially in U.S forces, the DivArty responce is quick, sometimes it is not, for various factors. My point being that assets belonging to lower units often get on target quicker. That's one reason mortars are popular.

I was indeed referring to the 105mm M3. It was indeed a shortened howitzer. However, its use as a IG was fairly short, BUT we did have them, at least for a while. The Germans probably made the most use of this class of weapon and the majority of them were 75mm which was less lethal than their 105mm howitzer.

Now I still can't agree with you that mortars with their high-angle fire are comparable to low-angle artillery in accuracy. High-angle fire is intrinsically less accurate than low-angle because the projectile is subject to winds and what-not for a longer period of time. Fin-stabilization accuracy is simply not comparable to rifled cannon in the WW2 era. Primarily this is due to the fact that the fin-stabilized round wobbles for a bit before it gets spinning properly. My experience on both types of weapons supports this.

 

Funny you mentioned the "short rounds". My company was participating in a CAX out in the Mojave Desert at 29 Palms. We were dug in on the side of a mountain, looking out across this huge basin. It was near dusk and they were supposed to fire a regimental time on target on a target the other side of the basin. The artillery was located behind us, a mile or more away on the back side of the mountain. It was still well over 100 degrees out and we were tired from the day plus digging our fighting holes. Everybody had stripped off their body armor and helmets, and we were standing there outside our holes in skivvy shirts and soft covers watching for the fireworks. We must have looked a lot like a community of prairie dogs standing their atop our holes. Anyway, rounds started going over and we were watching the explosions across the way. All of a sudden we heard this strange whoop, whoop, whoop sound and someone started yelling incoming. We all started jumping, and crawling into our holes, then there was this huge explosion in the middle of the perimeter, close enough it felt like it lifted you off the ground and pushed the air out of you. Then all you could hear was people yelling into and over the radios, "check fire, check fire". Then someone passed the word that it was all clear and for squad leaders to get a head count. Turns out a 155 round had impacted in the middle of the perimeter and even though there were pieces of shrapnel laying around everywhere, some pieces 8 inches or so long, sharp as a knife and probably weighing close to a pound, nobody got hurt. They had an investigation and the word that was passed to us, was that the battery in question had somehow, in the middle of the freakin' desert, gotten the powder for that round wet. The reason for the strange noise was because when the round left the tube, it was travelling slow enough it started tumbling end over end, and fell way short.