Possible Anti-Tank Rifle amendments

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Truscott Trotter
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Re: Possible Anti-Tank Rifle amendments

Post by Truscott Trotter »

Yes I think it was - or Gordon Rothman will try and find the site again.

Meanwhile this is fun
http://www.wwiiequipment.com/pencalc/

Actually not sure who author id
Ww2pen3.pdf

Munin
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Re: Possible Anti-Tank Rifle amendments

Post by Munin »

Theoretically speaking, you should be able to get moderately close by taking into account muzzle velocity, projectile weight, and projectile hardness/cross-section to determine armor penetration, but even those statistics are probably hard to come by. But at least that math would remove the variability in what constitutes "penetration," as you could test all theoretical projectiles against the same armor thickness/manufacture/orientation computationally.

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Seret
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Re: Possible Anti-Tank Rifle amendments

Post by Seret »

Munin wrote:
Tue Feb 04, 2020 12:05 am
Theoretically speaking, you should be able to get moderately close by taking into account muzzle velocity, projectile weight, and projectile hardness/cross-section to determine armor penetration, but even those statistics are probably hard to come by. But at least that math would remove the variability in what constitutes "penetration," as you could test all theoretical projectiles against the same armor thickness/manufacture/orientation computationally.
I'm going to put my engineer/armourer hat on here for a second and get technical:

That would give you the muzzle energy and areal density of the shot, but unfortunately that doesn't translate directly penetration performance. Terminal ballistics is complex, it's the kind of thing engineers weren't able to model until we developed things like 3D computer modelling (FEA, etc). Which is why in the past they relied on actual testing so much, it just wasn't possible to estimate performance in simulation. There's no simple mathematical model for it, it's all just empirical data.

If you were firing two different unitary penetrators against the same target then comparing muzzle energies would probably be in about the right ballpark. Unfortunately WW2 projectiles usually weren't unitary so terminal performance in contact with the target is complex to model accurately, even using a computer.

Bottom line: as wonky as it is, the empirical testing data will be far more accurate than any attempt to estimate it theoretically.

JimLeCat
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Re: Possible Anti-Tank Rifle amendments

Post by JimLeCat »

Not to mention that the armour varied in a host of properties and was commonly not uniform either through or across plates - and that's before you factor in composite armours!

Contrarius
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Re: Possible Anti-Tank Rifle amendments

Post by Contrarius »

So chaps, is there grounds to have two range bands above/below 24 inches? It would bring AT rifles more into line with comparable weapons like Piats, panzerschrecks/fausts and early bazookas.

Perhaps losing a die above 24 inches is excessive, but I suspect a good marksman could hit quite reliably at the ranges represented in CoC — 240 yards for a six foot table.

Most photos I’ve seen of Panzers knocked out in Poland show multiple hits.

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Seret
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Re: Possible Anti-Tank Rifle amendments

Post by Seret »

Contrarius wrote:
Tue Feb 04, 2020 1:39 pm
Most photos I’ve seen of Panzers knocked out in Poland show multiple hits.
Definitely. One of the problems with AT rifles is that even if the first hit was very effective the firer might not know. AT guns often kept shooting the same target until it burned. That's not going to happen with an AT rifle so a lot of tanks were probably hit far more than they actually needed to be, just to make sure.
Last edited by Seret on Wed Feb 05, 2020 10:55 am, edited 1 time in total.

Tomm
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Re: Possible Anti-Tank Rifle amendments

Post by Tomm »

Reading Chiukovs autobiography (obviously with a ton of salt) his AT rifles seem very effective against armour. More than I would expect under CoC rules.

Munin
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Re: Possible Anti-Tank Rifle amendments

Post by Munin »

Seret wrote:
Tue Feb 04, 2020 9:45 am
I'm going to put my engineer/armourer hat on here for a second and get technical:
Technical is good. 3D modeling/Finite Element Analysis is exactly what I was going for.
Seret wrote:
Tue Feb 04, 2020 9:45 am
Bottom line: as wonky as it is, the empirical testing data will be far more accurate than any attempt to estimate it theoretically.
I'm still not convinced that's the case, as at least the computational method allows you to remove variables (armor thickness/composition/angle, range etc) that existed and were rarely documented in the original studies.

Len Tracey
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Re: Possible Anti-Tank Rifle amendments

Post by Len Tracey »

ATR are an interesting subject that received a lot of attention between the wars. Most nations looked at them as a solution to the tank problem for frontline Infantry units and so developed or bought a version. The options came in roughly three variations: Heavy (20mm), Medium (14mm) and Light (8mm). Each was a trade off between size, portability and penetration. I've posted these before, but here is my translation of these types into CoC.

Heavy ATR: Heavy ATR (20mm) [AT 4, HE 1] require a crew of 5 and cannot move if the crew falls below 3 personnel, cannot move and fire.
Lahti L-39: (Finland) 20mm semi-auto, 50kg, MV 800m/s
Type 97: (Japan) 20mm semi-auto, 52kg, MV 790m/s
Solothurn S18/100: (NEI) 20mm semi-auto, 50kg, MV 735m/s

Medium ATR: Medium ATR (14mm) [AT 3, HE 1] require a crew of 2+ and, if the crew falls to 1 man, lose 1 pip from each movement dice and cannot move and fire. The Boys ATR only has AT 2 to reflect its low muzzle velocity.
Boys 0.55” ATR: (British Commonwealth, Belgium) 14mm bolt-action, 16kg, MV 884m/s
PTRD – 41: (Soviet Union) 14.5mm bolt-action, 17kg, MV 1114m/s [also PTRS semi-auto version 20kg]

Light ATR: Light ATR (7.9mm) [AT 2, HE 1] can be operated by a single man at no detriment.
Panzerbuchse PZB-39: (Germany) 7.9mm bolt-action, 11.6kg, MV 1210m/s
WZ-35: (Poland) 7.9mm bolt-action, 10kg, MV 1275m/s

NOTE: The Boys appears to have been the worst performing of the ATR, with the weight of a "medium" ATR but much low muzzle velocity and penetration more akin to that achieved by a "light" ATR.
Just some thoughts.

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Truscott Trotter
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Re: Possible Anti-Tank Rifle amendments

Post by Truscott Trotter »

Seems pretty spot on to me Len.

The semi auto doesn't seem to make much difference when you look at Boys training films they move that bolt quite quickly. 😁

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