Regarding AP for the German infantry guns.
They never received AP rounds, but HEAT (hollow-charge) rounds.
Was this ammo commonly used on the Western front in 1944-1945?
The HEAT (german: HL = Hohlladung) rounds for the infantry guns were used from the point in the war where they were first issued until the end of the war, as they were standard issue. Despite being actually outdated, the Germans kept producing le.IG 18 guns, and they were employed in IG Coys, Recon Bns and Cavalry Bns, serving as close support weapons (with HE, the main purpose) AND as antitank weapons.
I am not sure about the typical loadout per infantry gun, but it's pretty obvious that an IG ammo stock contained a certain amount of HL-grenades (HEAT).
A short study published in 1963 in the "Allgemeine schweizerische Militärzeitschrift" (Swiss Army military magazine) and authored by Major Gerhard Donat, Vienna (Austria), outlined/analyzed the ammunition expenditure for campaigns and major battles from 1939 to around 1943, but even more interesting, also detailed the FIRST LOADOUT a given gun gun had to receive (as of 1st of May 1944, according to Wehrmacht ordnance, see scan below).
The Wehrmacht conducted extensive studies that examined ammo expenditure under various conditions, which was important for planning of logistics and production. After the battle of Sevastopol the Germans could start to establish base expenditure figures for various conditions, so they separated expenditures during attacks and defensive operations for the following conditions (rough translation):
Attack
- a) progressing well
- b) difficult, tedious
- c) against fortress (Sevastopol)
Defense
- a) at calm Front
- b) during major offensives
The tables even contained small arms (down to Luger pistol) rounds and hand grenades and referred to an average expenditure per barrel during a period of 10 days and for a force with the size of an Army. For instance, an average number of 91 IG rounds (per barrel) was established for "light infantry grenades" (referring to the ammunition for light infantry guns) when an attack "progressed well", and 110 rounds, when the attack was "difficult, tedious".
The first loadout (as of 1st of May 1944):
The first loadout for a (single) light infantry gun amounted to 189 rounds (these were, as I outlined either here or in the Matrix forums, kept on the nearby ammunitions wagon, and the rest on the supply columns cars/wagons and at depots in the rear). I would have to invest some 60 or 80 USD and obtain a couple of German magazines (1960s) and one or another small book (1990) - from the publisher where Jentz used to publish his shorter papers - covering the infantry guns, in order to establish an exact amount, but it is safe to say that a certain amount of supply and depot space was reserved for maintaining the AT capability, means for HEAT rounds.
Sidenote: expenditure figures of the Artillery-Regiment 125 for the defensive battles at the Mius river (March 1942 - June 1942) and the follwing attack (July, attacking towards Caucasus in August and follwing battles in September), and then the readjustment (improving) of frontlines and the following defensive battles in November/December 1942 (Chir river battles?) are particularly interesting, as they are based on exact counts (posted in the unit's war diary) performed by that Artillery-Regiment (125), which didn't just list the rounds fired at Russian positions, but also Russan shells fired in the Regiment's sector.
There are also exact breakdowns (in percent) showing the times of highest activity of the Russian artillery, where you can see, that in April - June 1942 Russian artillery would usually conduct fire missions in the afternoon and evening and fall back to sporadic harrassment/inderdiction fire missions for the rest of the day/night or even complete silence. The study also stresses that Russian firing methods were inferior to the more effective German methods, which the Russians tried to compensate with higher expenditures. For instance, from April 15 to May 14 (1942), the Regiment fired 396 rounds with light and heavy field guns, while the Russians fired 1472 rounds. From May 15 to June 14, the Russians fired 3051 rounds, while the Regiment fired 998 rounds. During the first period, the Russians fired 3.71 times more rounds, and 3.06 times more during the second period, with the highest activity of the Russian artillery always occuring between 3 p.m. and 5 p.m. (April/May: 23%, May/June: 16.4%) and between 5 p.m. - 7 p.m. (April/May: 24%, May/June: 25.4%).
Back to the infantry guns:
The following link leads to a very detailed article authored by a German (living in the US), Thorsten Herbes, whose grandfather had served in the 352. Volksgrenadier-Division. He blends in personal accounts from his grandfather, Erich Michely (died in 2011), an NCO who led an IG platoon during the Battle of the Bulge, after he had served in Russia (2 deployments, wounded 1 or 2 times):
http://gottmituns.net/2012/12/22/me...oldier-during-the-battle-of-the-bulge-194445/
Erich Michely said:
As the advance troops of the 915th continued to wait near Bastendorf, Michely and his men made steady progress toward them. “We often moved cross-country, following the infantry and providing fire support where needed. I think we were also afraid to stay on the roads for too long, for fear of American [P-38] Lightnings.” Hindered by the rough terrain, the men were often forced to assist the horses in moving the guns. Many of the details of 8/915 route and events along the way have long left Michely’s memory, but several anecdotal stories remain. “The infantry at the front of the column needed artillery support and we had to get our guns up the hill to help them. The hill was so steep that we had to turn the guns around, with their barrels facing forward, hook all the horses to one gun at a time and push it up the slope ourselves. Eventually, we managed to get all four of them up the hill.” Michely continues: “I believe it was near Tandel where we came across two US tanks, unaware of our presence. We were looking down at them from an elevated position and our guns knocked both of them out. I don’t recall if any of the crew managed to get out.”[37] Given the horse-drawn means of transportation, Michely’s company always seemed to lag behind the advance infantry troops and thus avoided much of the combat they faced. “We maybe fired a dozen rounds or so throughout the entire Ardennes campaign.”
Herbes assumes that Michely's platoon was equipped with Infanterie-Geschütz 42 guns. The IG 42 was developed by Krupp after the French campaign had ended (1940) and the gun was supposed to replace the le.IG 18. With a weight of 590 kg, the IG 42 was considerably heavier than the horse-drawn version of the le.IG 18 (405 kg in transport mode, 400 kg when deployed), and still somewhat heavier than the le.IG 18 version with rubber tires for motorized units (515 kg in transport mode, 570 kg when deployed), but its barrel was 178.8 cm long, the muzzle velocity clearly higher (280 meters/second) and the max. range considerably higher (4800 meters). The designers already envisioned a dual role, so they added a feature that was unseen before on infantry guns: the gun could be traversed 78 degrees. For comparison: The le.IG 18's barrel could be traversed 11 degrees only, but the max elevation was 75.3 degrees. The IG 42's barrel could only be elevated to 32 degrees. This made high-angle fire on say trenches impossible, but the 75mm HE round could still blast off earth walls (protecting trenches) with a thickness of up to 1 meter, so the gun was capable to serve in its planned (dual) role.
Since the production of the HEAT (HL) round for the le.IG 18 had started already, the Wehrmacht canceled the production, but picked up the project in 1944 again (because the production of one le.IG 18 involved 1200 man-hours, some parts needed for the IG 42 could be produced in a shorter time, but also because gun losses had to be replaced) and ordered 1450 IG 42 guns, with the first batch issued to frontline units in October 1944. Michely reports about flat tires, which would be odd for le.IG 18s, as his unit clearly operated horse-drawn guns, and as le.IG 18 guns with rubber tires were usually issued to motorized units, only.
In turn, most - if not all - IG 42 guns were issued with either solid rubber tires or with air-filled rubber tires, so the author's assumption that Michely commanded a IG 42 platoon may actually be correct.
Also, Michely reports that his "unit" (Bn/Regiment/Division ???) had been equipped with Sturmgewehr 44 assault rifles, so it seems to be a fair conclusion that they also got some of the relatively new Infantry guns (either Infanteriegeschütz 42 or Infanteriegeschütz 37, see pictures below).
EDIT : Despite the gun looking like a PaK (AT) gun, its pretty low velocity made it impractical to fire AP rounds with it, as AP shells would have lacked the kinetic energy to penetrate. The only solution for the dual-role was to equip it with HEAT rounds.
These guns were not to serve as dedicated AT guns, but since the 88mm PaK 43 or the PaK 43/41 were employed in Panzerjäger units, as Schwerpunkt defense, and even often held back as Korps reserve, the AT capabilities of the light infantry guns were desperately needed.
The effective AT range of a le.IG 18 (with a pretty short barrel) was probably 300 meters and below, as anything above that range must have been a curved trajectory (hard to aim/calculate the shot). With the comparably long barrel of an IG 42 or IG 37, I could imagine that the max effective AT range was somewhat higher, but I do not have exact numbers. The le.IG 18's field manual from 1940 stresses that enemy armored cars can be engaged (with HE rounds) at ranges of ~300 meters or below, and that a forward defensive perimeter, road block or "hold up" should be established at around 300 meters, so that the le.IG 18 can engage with a flat (trajectory) shot. The HEAT rounds for the gun did not exist yet when that version of the manual was printed.
Infanteriegeschütz 42 with solid rubber tires:
IG 42 with air-filled tires:
The Infanteriegeschütz 37 (~1304 guns were still in service at the end of the war) was orginally introduced as a stop-gap measure (easier to produce, less parts, either mounted on a PaK 36 carriage or on captured Russian carriages) and designated 75mm-PaK 37, but it was in fact a mix of an infantry gun and an AT gun, and - afaik - used the barrels that were originally designed for the IG 42 (traverse: 60 degrees). It never received AP rounds, as the muzzle velocity (280 m/sec with HE : max range 5150 meters - as the barrel was a tick longer than the IG 42's barrel, 395 meters/sec with HEAT) was too low, so it received HEAT rounds. Since the gun fired the same rounds as the le.IG 18, the gun was re-classed in May 1944 and then designated Infanteriegeschütz 37. The Germans started to issue the first batch of guns to troops in June 1944:
They were also mainly foot-bound after they reached the front and probably didn't want to lug around extra AP ammo when the AT sections were responsible for that. What do you think?
Vital parts of the first loadout were always kept with the marching column, the rest was further behind.
In Michely's anecdote, the gun crews had "parked" the horses towing the ammo wagons right on the street (as they had not deployed yet), when they got surprised by the US attack in Merzig.
SIDENOTE: The personal account of Generalmajor Erich Otto Schmidt, the commander of the 352. Volksgrenadier-Division, regarding the equipment and combat readyness:
According to Generalmajor Erich Otto Schmidt, Commander of the 352nd VGD: “I took over the division in October 1944. We continued to train until 15 November when we were moved to Bitburg, in the Eifel region, where we continued to train and supplement our equipment. Near the end of November, the division took over a section of the Westwall between Vianden and Echternach. 48 hours prior to the attack on 16 December, the division was led to its jumping off points between Roth and Wallendorf.”[12] Generalmajor Schmidt continues: “The division was formed and equipped according to standard specifications for Volksgrenadier divisions, with Ersatz troops drawn from navy and air force ranks.”[13] Prior to the attack, Schmidt rated his troops:[14]
Enlisted Personnel: Age 23 -30, not enough training, no land or combat experience, not seen action. Full strength.
Non-commissioned Officers: Mostly navy troops, most lack front experience. 75% strength.
Officers: Varied front experience. Full strength.
Infantry: Good fighting spirit in Regiments 914 and 915. Lacks training and front experience.
Equipment: Mostly complete. Missing 35% of radios for fire direction, 30% of assault guns, 25% assault rifles.
In general terms, the 352nd VGD was well equipped for 1944 but lacked in experience. The 352nd was made up of three infantry regiments (914th, 915th and 916th), an artillery regiment, one cavalry battalion, one anti-tank battalion as well as anti-aircraft, engineer and signal battalions. At full strength, the division made up about 13,000 troops.[15] Unteroffizier Erich Michely, veteran of two tours of duty on the Eastern Front, was assigned to 8th (Heavy) Company, 2nd Battalion, 915th Volksgrenadier Regiment, as a light infantry gun crew leader.
