Small Arms Fire vs. Gunshields - should it be penetrating?

[Little_Black_Devil]

Something I've been attempting to look into, is the interaction between small arms and the gunshields on field pieces.

Needless to say, there doesn't appear to be a great deal of conclusive information out there.

Perhaps some of the experts out there could shed some light on this elusive issue.

I believe, from my own experience that gunshields are not entirely bulletproof - having seen the 10mm roof plate of a modern AFV cleanly penetrated by a .303 hunting rifle. Gunshields may stop most small arms at range, but as the range deminishes, so too does the shields ability to stop bullets.

However, I find this difficult to substantiate through other verifiable sources.

I realize that there were all sorts of different gunshields, some perhaps which may have even been purpose designed to take small arms fire (like the Pak38 and Pak40 for instance). Most others I would hazzard to say, are likely constructed of softer, lighter metals - and are not actually "armour" in the conventional sense - though I could be wrong.

I also wonder if there was a distinct difference between howitzer gunshields and anti-tank gun-gunshields.

The gunshield on the Pak38 for instance, consists of two seperate plates, each 4mm in thickness, spaced 25mm apart. I'm not entirely sure if they were indeed armoured plate, or a softer steel. This type of configuration would seem to be designed to defelct and otherwise protect the guncrew from small arms. Was it effective to that end?

To the best of my knowledge, gunshields are in place to protect gun crews from srapnel and debris being kicked up. They may inadvertently stop some small arms rounds but I can't see most of them flat out stopping a hail of small arms fire at closeer ranges, like 100-200m.

Can anyone comment on this with more specifics?

Thx

[Bastables]

German Reports May 1941 on the exp of PaKs note that PaK 37 and PaK 38 where not penatrated by rifle (303 nor BESA 7,92) fire nor shell Splinters. After the battle of France British light tanks were reported as ineffective versus German anti-tank guns.

German experience is the exact opposite, MG 34s fired S.M.K or AP rounds, gunnery manual D613/10 stated that enemy gunshields could be penatrated at up to 500m. British reports in Nth Africa concur in that British 2pdr anti tank guns that held their fire until 600yds have their crews frequently knocked out by MG fire that penatrated their shields.

[rexford]

The difference between German and British gun shields is the type of armor.

Germans used face-hardened armor on the shields, British didn't.

Face-hardened armor becomes more and more effective against hits, compared to homogeneous armor, as the projectile diameter decreases.

Spaced plates on the shield might also defeat rifle bullets by having the first plate blunt the nose of the round, which decreases the performance against the second plate.

Firing tests with 57mm through 90mm ammo also show that a thin spaced plate in front of the main armor can shatter the round and reduce ability against main armor.

[ July 11, 2003, 09:08 PM: Message edited by: rexford ]

[John Kettler]

LBD,

I don't have the relevant reference to hand, yet distinctly recall reading that the Pak 40's shield was specifically designed to defeat the 14.5mm

Soviet antitank rifle (ATR) projectiles. Presumably, this design requirement came about from 14.5mm shield penetrations on earlier Pak models. Normally, a gun shield is to protect against shell splinters and flying debris,and ability to defeat rifle and rifle caliber LMG fire is a good idea, but even that level of protection is inadequate against a high velocity, heavy bullet more suited to a light cannon.

Hope this helps.

Regards,

John Kettler

[rexford]

Originally posted by John Kettler:

LBD,

I don't have the relevant reference to hand, yet distinctly recall reading that the Pak 40's shield was specifically designed to defeat the 14.5mm

Soviet antitank rifle (ATR) projectiles. Presumably, this design requirement came about from 14.5mm shield penetrations on earlier Pak models. Normally, a gun shield is to protect against shell splinters and flying debris,and ability to defeat rifle and rifle caliber LMG fire is a good idea, but even that level of protection is inadequate against a high velocity, heavy bullet more suited to a light cannon.

Hope this helps.

Regards,

John Kettler

Russian anti-tank rifles could penetrate about 30mm at close ranges.

[Little_Black_Devil]

Wow - thanks for the responses.

I'm begining to think that the issue of small arms vs gunshields is not as cut and dried as I originally thought it was.

Within the context of Combat Mission, I do wonder when and if the Germans ever stopped making their armour piercing MG round as fired by the MG-34 and MG-42 respectively (whether it was from a vehicle mount or not). Obviously, the early war years would have seen the continual availability of the Patr Smk (armour piercing round) for the German MG-34. This makes me wonder if small arms fire (and specific munition - i.e., AP) will be taken into account for CMAK. Obviously, if the tungsten cored Patr Smk ammunition becomes less and less available, the so too would the German "advantage" over allied gunshields disapear.

Having read some of your guys comments, and also having refered to my newly aquired copy of Thomas L. Jentz's "Tank Combat in North Africa" I'am begining to see a distinct difference between Allied gunshields and German gunshields.

That difference would indeed seem to be, as Rexford pointed out, the difference between face hardened armour on the German gunshields vs. the rolled homogeneous armour on the allied guns.

What I found significant, was that Allied guns were on the whole, suceptable to the MG-34's armour piercing rounds up to 500m - and in North Africa, regularly taken out by machine gun fire.

In contrast, the German guns with their face hardened armoured gunshields, seem to have resisted small arms fire. Partially because the Allies mostly used standard ball ammunition - which was ineffective against the German gunshields, and partially because of the German practice of using face hardened armour on their gunshields. Only armour piercing rounds, fired say by the .5 inch Vickers were able to penetrate the German gunshields.

It seems what we end up with is a stark contrast between Allied and German anti-tank guns respective abilities to resist small arms fire, where German guns on the whole were well protected and Allied guns were not.

With respect to the dual-layered gunshields seen on a number of German guns - I also wonder if both layers were face hardened armour, or if the frontal layer would have been of a softer metal.

Regardless their composition, the dual layers would seem to add an additional level of protection. I wonder indeed just how much protection they would have provided against enemy anti-tank rifles or larger calibre machine guns.

In any event - does this analysis seem reasonable?

Bastables - any idea where I could get my hands on those reports you mentioned and others like them?

Thanks again guys.

[YankeeDog]

That the allies used primarily ball ammunition is not true in all cases. There is at least two major exceptions that I know of: the BAR and the M2 .50 cal MG.

While the BAR had several types of ammunition available to it, including ball and AP and tracer, apparently from very early on, BAR gunners were primarily equipped with AP ammo to the point where ball ammo for BARs was actually uncommon (though of course there was plenty of ball around in the same caliber for other weapons). Apparently the AP was preferred for its superior penetration into cover like buildings and vegetation.

I have never seen detailed penetration stats for the .30-'06 AP round, but it would be interesting to know if had enough penetration to get though lighter gunshields, or even some of the lighter Axis armored vehicles. It would also be interesting to know whether infantry started using AP over ball ammo in the M1917 and M1919 .30 cal MGs.

In the case of the M2 .50 cal MG, it obviously had an AP round that was used extensively for aircraft and AA loads. Most of what I have read also indicates that one in every 4 or 5 rounds in the standard infantry load was an AP round as well.

In any event, I would be extremely skeptical that the 4mm + 4mm of the PaK 38's gun shield could stand up to a .5in AP round from an M2, face hardened or no. I have never seen a conclusive firing test proving this, though.

Cheers,

YD

[rexford]

500 yard penetration of U.S. machine gun bullets:

cal. .30 AP M2

==============

166 grains

24" barrel

2775 feet per second muzzle velocity

0.302" homogeneous (7.7mm)

0.190" face-hardened (4.8mm)

cal. .50 AP M2

==============

708 grains

36" and 45" barrel

2835 and 2935 feet per second muzzle velocity

shorter barrel

0.742" homogeneous (18.8mm)

0.530" face-hardened (13.5mm)

longer barrel

0.790" homogeneous (20.1mm)

0.595" face-hardened (15.1mm)

If the outer plate on the 50mm Pak gunshield succeeded in shattering the bullets or blunted their tips, it might result in a boost of the armor resistance over the sum of the two shield thicknesses.

When two plates are spaced, homogeneous armor resistance will be less than the sum of the plates unless the outer plate shatters or blunts the projectile before it hits the inner armor.

Source for above data is TM9-1907, Ballistics Data: Performance of Ammunition (1948)

[Little_Black_Devil]

So - does anyone know if the tungsten cored AP ammo as fired by German MG's was ever phased out (due to the shortage of tungsten) - or were they prevelent right through the duration of the war?