U.S. 57mm AT guns firing AP spew death and destruction

[Drifter Man 124]

Following a report by Nemesis from the Few Good Men Forum (https://www.thefewgoodmen.com/thefgmforum/threads/new-ladder-report-submitted.31582/), who mentioned that his men got badly shot up by U.S. 57mm guns firing AP, I set up a simple test scenario to confirm:

• 57mm HE has surprisingly strong effect for its size, but at least it is HE
• 57mm AP kills infantry far and wide - it looks more like a medium-caliber HE round than a solid shot or an AP shell with a small filling charge.

See the linked file save (hotseat mode, no passwords). Germans have cover arcs so they don't shoot back. Just remove the cover arcs from the ATG's, which had already spent their HE supply using area fire. Within a few turns the German battalion will be obliterated with 57mm AP.

https://dl.dropboxusercontent.com/s/agbb8i6lah53c22/57mm atg test.bts

Interestingly, the British 6pdr AP does not have this problem.

[user1000 91]

what is happening to the high velocity shell when it hits that type of ground ? I would say it is shattering into shrapnel, also ground could be kicking up rocks and splinters etc. many of the guys are not dying just taken out of action. (incapacitated) Looks normal to me, thats a lot of AT guns!

Edited August 18, 2020 by user1000

[Drifter Man 124]

I have no issue with AP rounds producing casualties among infantry, but they should be less effective, not more effective, than HE - otherwise there would be no point in having HE in the first place. In addition, the effect should be consistent across all guns. There is no reason for the U.S. 57mm AP to be this effective, while the British 6pdr AP, fired by essentially the same weapon, has little effect against infantry.

https://dl.dropboxusercontent.com/s/urhq87zg150h03v/atg%20test.bts

Under the link above you can find a (hopefully) more convincing test setup with the following guns:

• U.S. 57mm ATG firing HE - for reference
• U.S. 57mm ATG firing AP
• British 6pdr firing AP
• British 17pdr firing AP
• U.S. 76mm ATG firing AP
• U.S. M10 GMC firing AP
• German 5cm PaK38 firing AP
• German 7.5cm PaK40 firing AP
• German 7.62cm PaK36(r) firing AP

You can select any of the guns and give it a target order to open fire.

The test shows all U.S. and German guns in this setup can produce numerous casualties in the 50-100 m radius from impact with AP rounds. In contrast, the British guns have hardly any effect, and the effect is local to where round has hit. So it's not just the 57mm ATG - it appears to be common all U.S. and German guns, but not British guns, in CMBN.

One doesn't get to see this often because AP don't get used against soft targets often.

[akd 616]

German and US is APHE.  British is AP solid shot (or unfilled AP).  In theory, APHE should generate a smaller number of larger fragments that have higher penetration and travel further, so you’d really need to do some extensive testing versus HE to determine a difference in outcomes based on range from the burst.

[user1000 91]

engaging troops with an AT gun...

Real life ...... wouldn't you just use your rifle for that?

[Drifter Man 124]

12 hours ago, akd said:

German and US is APHE.  British is AP solid shot (or unfilled AP).

That's a possible explanation for the difference. I don't have great references for ammunition but apparently U.S. 57mm guns had both solid shot and APHE, whereas British had only solid shot. The game isn't clear about what is what, calling both just AP.

I would just recommend that BFC check if the numbers for the AP effect and blast radius against soft targets if it is what they intended. Even without extensive testing - and I can do some serious testing when it comes to it 🙂 - I can see they are of the same order as HE.

And for the players, keep this in mind for next time when your opponent's AT guns run out of HE. You may get an unpleasant surprise.

[Bulletpoint 1,074]

Would APHE even explode when hitting the ground? Wasn't the fuse designed to only trigger against armour?

[Drifter Man 124]

3 hours ago, Bulletpoint said:

Would APHE even explode when hitting the ground? Wasn't the fuse designed to only trigger against armour?

Good point, but I think it would explode. I don't know much about AT gun ammunition but I've read a bit about naval guns - I understand that an AP would have a fuse that is less sensitive to acceleration than a HE. So it would not explode when passing through a thin plate, but when hitting the ground I imagine it would see enough acceleration to set off the filler.

It's the effect of the subsequent explosion in CMBN that I find hard to accept.

[Bulletpoint 1,074]

6 minutes ago, Drifter Man said:

It's the effect of the subsequent explosion in CMBN that I find hard to accept.

Agreed. I've often noticed that AP shells seemed to have a large burst effect. Previously, rebounding AP shells would explode when hitting the ground. This explosion seemed powerful, dropping infantry quite far away. But in recent patches, those bouncing shells no longer explode when hitting the ground (a change I was very happy with).

Edited August 27, 2020 by Bulletpoint

[Drifter Man 124]

On 8/27/2020 at 7:12 PM, Bulletpoint said:

Previously, rebounding AP shells would explode when hitting the ground. This explosion seemed powerful, dropping infantry quite far away. But in recent patches, those bouncing shells no longer explode when hitting the ground (a change I was very happy with).

Interesting and agree that it's good that this has changed. I'd say that in many cases a deflected round would not be in a fit state to explode.

I though a bit about the naval information I mentioned - it doesn't apply here. Naval AP shell fuses were less sensitive to acceleration because of the way naval armor was built up, with lighter armored decks specifically designed to set off the fuse prematurely, before the projectile reaches the ship's vitals. AFV armor is different, with only one thick plate (hopefully) strong enough to defeat the projectile.

But that's getting a little off topic, there's still a good reason to think that an AP would explode upon hitting the ground.