Early War Problems with 45mm Ammo

[rexford]

Valera Potapov noted in the past that 45mm ammunition suffered from quality problems during late 1941 and early 1942, leading to decreased penetration.

Here are some penetration figures from German and Russian sources that show the extent of the problem. Data is for 45mm L46 gun firing APBC of some sort. Numbers in brackets are 0 degree estimates from 30 degree figures, using slope effects for APBC.

Armor is homogeneous.

45mm APBC

1940 Russian Penetration Tests, 0 Degree Impact

55mm at 300m

45mm at 600m

40mm at 1000m

30mm at 1500m

This would be pre-war, and the numbers are fairly close to what we predict for 45mm APBC.

1942 German Tests at 30 Degrees

40mm at 100m (46mm at 0 degrees)

28mm at 500m (31mm at 0 degrees)

19mm at 1000m (20mm at 0 degrees)

Vasiliy Fofanov has posted, on Yahoo!Tankers site, that 45mm gun had trouble penetrating front and side armor of panzers beyond 500m during 1941. He stated that one of David Glantz' books includes material on the inability of 45mm anti-tank guns to defeat panzers during June 1941.

The 1942 German tests show a great drop in penetration from 1940 tests.

The problem was so bad, according to Fofanov's recounting of the passage, that the panzer crews referred to the 45mm ATG as the Russian equivalent of the German 37mm door knocker.

I will try to find the book by Glantz that is supposed to include the above passage.

German Data in Panzertruppen 1943-1945

30 degree penetration by 45mm APBC

42mm at 100m (48mm at 0 degrees)

35mm at 500m (40mm at 0 degrees)

28mm at 1000m (31mm at 0 degrees)

23mm at 1500m (25mm at 0 degrees)

My estimates at 0 Degrees

64mm at 100m

58mm at 250m

49mm at 500m

43mm at 750m

38mm at 1000m

32mm at 1500m

The 1940 Russian tests result in figures that are close to my estimates. Panzertruppen and 1942 German figures show decline in penetration performance.

1940 and 1942 test data from Miles Krogfus.

[rexford]

This is from Vasiliy Fofanov's posts on Yahoo!Tankers site:

"Considering that the war diaries of advancing

Germans had as early as June notes that Soviet 45mm guns were just as useless against their panzers as their own 'door-knockers' against

T-34 (see e.g. Glantz "The initial period of war on the Eastern Front")"

Vasiliy was forwarding the idea that Russian 45mm ammo was questionable during June 1941 and did not suffer any major decrease.

[JasonC]

In his Kursk book, Glantz has a passage on Russian ATGs that reads as follows (pg 38 of The Battle of Kursk) -

"The Red Army's antitank weapons in 1943 were a mixed bag and generally inferior to the Wehrmatcht's. By the summer of 1943, the Red Army as finally begining to receive the excellent 57mm ZIS-2 57mm towed ATG, deferred for political reasons in 1941. It was more than adequate to deal with the standard German tanks of the day such as the Pz IV. However it was inadequate in frontal engagements against the new German Panther or Tiger tanks. As a result of the 57mm's delayed entry into service, the Red Army was still dependent on large numbers of the prewar 45mm Model 1932 ATG, which by 1943 was completely inadequate to penetrate the front of any German medium tank. In 1943, a modernization program was begun on these weapons resulting in the 45mm Model 1943 ATG, which had modest capabilities against the lighter German armored vehicles."

I find nothing on the subject in the Don to the Dnepr volume. The Kursk soviet staff study volume focuses on deployment issues and number of weapons, and the general use of "gun fronts", but not on the particulars of penetration by 45mm.

All the above passage says, of course, is that the early model 45mm did not penetrate 80mm flat armor. It implies, but no more than implies, that modernized 45mm had some capability against 50mm or 30mm+30mm armor, on older Pz IIIs and short IVs.

Other sources I have seen date the 45mm modernization to 1942, not 1943. The model M-1942 I've seen rated to penetrate 60mm at 500 and 50mm at 1000 yards, vertical. The model 37 I've seen 43mm and 35mm for those ranges. I've seen 30 degree figures for the 1932 of 35mm and 28mm, which seem to me fairly comparable to the model 37 flat angle figures, and agree with the Panzertruppen numbers you cite.

Trouble penetrating front armor of Panzers in 1941 is an ambiguous statement, obviously. The most recent models had 50mm or 30+30mm front armor by then, and so one would not expect them to be penetrated by the prewar 45mm ATGs. But the pre-H IIIs and pre-E IVs had only 30mm front and sides, without significant slope either. From the Panzertruppen 30 degree figures, you'd expect modest side angle would keep the penetration distance under 1 km, but that they would still have no serious trouble at 500m.

Incidentally, there are also numerous cases of Panthers penetrated by 45mm from the side in the Kursk reporting on Panther losses. The ranges, unfortunately, are usually not available. But that means they did penetrate 40mm armor pretty routinely, at one point anyway. It seems to me unlikely, on its face, that they were routinely defeated by near-vertical 30mm armor earlier.

[ February 27, 2002, 10:05 PM: Message edited by: JasonC ]

[MajorBooBoo]

Ammunition

The Soviets were in the process of expanding their ammunition production facilities when the Germans attacked. The numerous incidents with neighboring states before the German invasion had revealed that ammunition production was grossly insufficient. Had the invasion been delayed until 1942 the new and expanded facilities would have been on line, alleviating the shortages that plagued the Soviets in the first year of the war as pre-war stockpiles were either overrun or consumed.

Unlike the artillery factories, Soviet ammunition plants were concentrated in the Donbass Basin and in the Ukraine which were overrun by the Germans during the fall. Some 303 factories were lost with a capacity of over 100 million artillery shells, 32 million mortar shells and 24 million aerial bombs. This produced a huge disparity between artillery gun production, which was less affected, and ammunition production. The table below shows the increases in production between the second quarter of 1941 and the third quarter of 1942. Note how gun production increased by a factor of six, but ammunition only by a factor of three.

http://members.tripod.com/~Sturmvogel/SovWarProd.html

The German invasion caught a number of Soviet artillery factories in transition between models as Stalin had ordered cessation of 45mm anti-tank and 76mm regimental gun production in January 1941 on the recommendation of his imbecilic chief of artillery, Marshall Kulik. Kulik had convinced himself, based on sketchy intelligence reports, that they were incapable of penetrating the armor on the mythical new generation of German heavy tanks! They were to be replaced with 107mm guns that were capable of penetrating any known tank.

It would seem that the soviets could have lost some tech know-how after the start of the war when the ammunition factories were overun.

[JasonC]

Sorry Major BB, but that makes little sense. If that were the cause of a serious difference in ammo, then the rounds already available before the invasion would be fine, while the ones produced later would be substandard.

But we know the later rounds from the same guns penetrated Panther sides, 40mm. And the question is whether some early ammo deficiency led to substandard penetration performance, under 30mm. Which would be the prewar, stockpiled ammo, talking about fights in 1941. So if it were just disruption of production as you suggest, the timing of the deficiency would be in the wrong place. It would start good and get worse, instead of starting bad and getting better. Unless it went both ways - started good, got worse, and improved again, I suppose.

I think it is more likely the one German test report was just from a gun with an overly worn barrel (too many rounds through, lower MV achieved), or some such. Unless I see more combat reports confirming that 45mm AP routinely failed against 30mm armor surfaces in 1941, which just a general statement "unable to penetrate German panzers" hardly amounts to, since there were already German III Hs and IV Es in the fleet by then, with 50-60mm armor, which we know the early 45mm couldn't penetrate at range.

[ February 28, 2002, 12:51 AM: Message edited by: JasonC ]

[rune]

Some clarifications:

The 45mm Model 42 was designed in 42, hence the name, but production started in 1943. Source: The Red Army Handbook.

The Soviets admit the ammo velocity dropped off sooner then their CALCULATED penetration on the model 37. Also the shells shattered more then expected. Rexford can post his source if he deems it necessary.

For the Model 42, at 500 meters at 90 degrees, the Red Army handbook has penetration at 61mm.

Rune

[MajorBooBoo]

Originally posted by JasonC:

Sorry Major BB, but that makes little sense. If that were the cause of a serious difference in ammo, then the rounds already available before the invasion would be fine, while the ones produced later would be substandard.

They were in a state of expansion. That could mean that there were new 45mm plants coming on line and grasping with QC issues. Hence a difference in performance of product.

Its certainly interesting information non-the-less. Did the germans capture whole plants capable of manufacturing ammo for 76mm field guns, 120mm mortars, etc.?

I recall that the ammo dumps were very close to the front, so by retreating, the russians really got a double whammy. Losing ammo dumps and factories.

[rexford]

Originally posted by rune:

Some clarifications:

The 45mm Model 42 was designed in 42, hence the name, but production started in 1943. Source: The Red Army Handbook.

The Soviets admit the ammo velocity dropped off sooner then their CALCULATED penetration on the model 37. Also the shells shattered more then expected.

Rune

What is the source of the above information?

Thanks.

Lorrin

[rexford]

Originally posted by MajorBooBoo:

[QB]Ammunition

The Soviets were in the process of expanding their ammunition production facilities when the Germans attacked. The numerous incidents with neighboring states before the German invasion had revealed that ammunition production was grossly insufficient. Had the invasion been delayed until 1942 the new and expanded facilities would have been on line, alleviating the shortages that plagued the Soviets in the first year of the war as pre-war stockpiles were either overrun or consumed.

What is the source of the above statement?

Thanks for the great response.

Lorrin

[rexford]

Originally posted by rexford:

[QB]This is from Vasiliy Fofanov's posts on Yahoo!Tankers site:

"Considering that the war diaries of advancing

Germans had as early as June notes that Soviet 45mm guns were just as useless against their panzers as their own 'door-knockers' against

T-34 (see e.g. Glantz "The initial period of war on the Eastern Front")"

Is the above statement consistent with Glantz' book?

[rexford]

Poor performance of 45mm anti-tank guns against 30mm German plates during 1941 can be supported without assumption of ammunition problems or inferior quality. Basic premise, as put forward by Vasiliy Fofanov, is that great majority of 45mm ammunition was uncapped AP rounds.

Russian Battlefield presents test data (80%) success for 45mm L46 uncapped AP, which was converted to 50% success criteria against rolled homogeneous armor:

54mm at 100m

40mm at 500m

27mm at 1000m

19mm at 1500m

Above data is fairly consistent with DeMarre estimates from Russian Battlefield test data for 85mm, 100mm and 122mm AP at 50% success. It is also worth noting that Russian Battlefield penetration figures for 45mm uncapped AP display a greater drop-off in velocity and penetration with range than predicted by William Juren's ballistic analysis methodology, which is also consistent with information provided by Mr. Fofanov.

Penetration against face-hardened armor can be estimated by comparison to other AP rounds, using the Krupp equation, and following figures apply for 45mm L46 uncapped AP:

42mm at 100m

32mm at 500m

23mm at 1000m

17mm at 1500m

Above figures are based on standard quality projectile with same metal and nose characteristics as 85mm, 100mm and 122mm AP.

Penetration range for 45mm L46 against 30mm/10 degree face-hardened driver plate on PzkPfw IIIG would be exactly 500m if no horizontal side angle exists, and appears to be consistent with combat reports noted by Mr. Fofanov.

Following figures apply to uncapped AP fired by 45mm L66 gun:

Rolled Homogeneous

60mm at 100m

45mm at 500m

31mm at 1000m

21mm at 1500m

Face-Hardened

47mm at 100m

36mm at 500m

26mm at 1000m

19mm at 1500m

In view of above analysis, Armor and Gunnery book requires revision to include 45mm uncapped AP if combat against panzers is to be correctly modeled. Numbers provided by Mr. Fofanov suggest that 45mm uncapped AP was primary round for that gun during 1940 and 1941.

Information provided on other sites suggests that initial stocks of uncapped AP may have been rapidly depleted as Germans overran ammunition stockpiles or ammo was used. It is not known at this point if ratio of AP to APBC rounds changed as war progressed and Germans overran Russia.

[John D Salt]

Originally posted by rexford:

Poor performance of 45mm anti-tank guns against 30mm German plates during 1941 can be supported without assumption of ammunition problems or inferior quality. Basic premise, as put forward by Vasiliy Fofanov, is that great majority of 45mm ammunition was uncapped AP rounds.

[Much detailed & interesting discussion snipped]

Was the main armour of any German tank face-hardened (FH) plate? I was under the impression that the basic armour was machineable-quality (MQ) homeogenous plate, with FH added on to the front. In those cases where additional armour was added, the armour thickness is 30 + 30mm, pretty much beyond the capability of the 45mm L46 at any angle or range whatever the armour type and ammunition nature used (OK, apart from APCR).

As far as I can make out from Chamberlain & Ellis, the 30+30 frontal armour fit would have been pretty typical for Pz III Ausf F, G and H armed with the short 5cm gun. I'm not sure what fraction of Pz IIIs at the time of Barbarossa were still making do with the 3.7cm gun and 30mm armour, but I would guess that, as the upgrades of gun and armour seem to have been done together, armament fit would be a better guide to armour than would Ausfuhrung.

The inadequacy of the British 2-pdr in North Africa is often attributed (as it was at the time) to the German use of face-hardened armour and the unavailability of capped shot prior to May 1942, but it seems to me that the effect would be largely irrelevant given the gun's inability to overmatch 60mm plate however arranged.

For simulation purposes, ISTM that the important thing to model is that weapons like the 2-pdr, 37mm M6, 45mm L46 and 50mm L42 can't penetrate the noses of 30+30mm armnoured Pz IIIs at battle ranges.

If there are sources indicating that the Soviet 45mm consistently had trouble getting through the _side_ plates of Pz IIIs or IVs, then that might indicate that amn quality is a problem. On the other hand, small-calibre (under 57mm, say) weapons are likely to have poor behind-armour effects after penetration, and the 2-pounder had a habit of shedding its tracer element, which gave the erroneous impression that successful penetrations had "bounced off". One might also suspect that with a fairly rapid-firing weapon, a gunner might put several shots into a target before it is seen to brew up or the crew bail-out, and so think that (say) it had taken three shots to get a penetration when in fact the first hit had been successful.

By the way, is "APBC" an accepted abbreviation or a repeated typo? I've never seen it before, but I would assume that it indicates an AP round with a ballistic cap but no piercing cap. I'm not quite sure why one would need a ballistic cap alone unless the shape of the round was pretty odd.

All the best,

John.

[Jeff Duquette]

John Said If there are sources indicating that the Soviet 45mm consistently had trouble getting through the _side_ plates of Pz IIIs or IVs, then that might indicate that amn quality is a problem. On the other hand, small-calibre (under 57mm, say) weapons are likely to have poor behind-armour effects after penetration, and the 2-pounder had a habit of shedding its tracer element, which gave the erroneous impression that successful penetrations had "bounced off". One might also suspect that with a fairly rapid-firing weapon, a gunner might put several shots into a target before it is seen to brew up or the crew bail-out, and so think that (say) it had taken three shots to get a penetration when in fact the first hit had been successful.

I think it is interesting to note that this habit of over killing a target may not have been restricted to high firing rate smaller-bore main-guns.

There is a rather famous bit of film footage of an M-26 Pershing engaging a Panther in the streets of Cologne, 1945. If one slows the video down it is apparent that the Pershing fires 4 or 5 armored piercing rounds into the side of the Panther at ranges of less than 100 yards. The Panther clearly brews-up after the second hit…the hole in the upper side hull from the first penetration is quite evident in the film and flames within the tank can be seen through the penetration…smoke is also billowing up through the open hatches. The Panther's Turret commander, driver and co-driver are all seen trying to bail out after the first 90mm round penetrates. The second or third round apparently severs the Tank Commanders legs and he dies while trying to escape from his turret hatch. It is a very telling piece of film regarding the nature of tank combat as it quickly becomes evident during the very harsh brew-up that the TC is burning while half his body remains positioned in his turret hatch. The Pershing fires one or two more rounds into the Panther…difficult to tell the exact number at this point as the camera is shaking wildly from the concussion of the 90mm firing.

The co-driver was apparently killed by MG fire while scrambling from his hatch. The driver clearly escapes and is seen running from the burning Panther. Presumably the gunner and loader were consumed in the brew-up as there was no evidence in the film of either making an escape.

John Said By the way, is "APBC" an accepted abbreviation or a repeated typo? I've never seen it before, but I would assume that it indicates an AP round with a ballistic cap but no piercing cap. I'm not quite sure why one would need a ballistic cap alone unless the shape of the round was pretty odd.

Soviet APBC was indeed armored piercing with ballistic cap. The penetrator is actually blunt nosed. If you examine a cutway of APBC it looks very much like APCBC, with the exception that the position normally occupied by a seperate penetration cap actually gives the impression of a penetration cap cast monolithic with the penetrator.

Of interest is a Soviet design feature of APBC where by circumferential groves were scribed around the upper portion of the penetrator to promote breakaway of the flat nose portion of the penetrator during perforation. Penetrative caps per say, were not apparently used, but the Russians favored machining these circumferential grooves, generally two, onto the ogive. The head would in theory break away leaving the remainder of the projectile undamaged during perforation. I beleive this was supposed to give APBC a pseudo-penetration cap action and was added to reduce shattering potential of the projectile at the higher velocities. One would think that the use of breakaway points\grooves might actually encourage shatter by providing weak zones in the penetrator.

[ March 02, 2002, 01:41 PM: Message edited by: Jeff Duquette ]