AP vs Bunker/Pillboxes

[jivemi]

In scenario #456, Makin Atoll, the US forces have CS and light tanks with max armor penetration of 8 (L31 75mm) and 6 (L57 37mm) respectively. Yet on a number of occasions they were able to take out bunkers and pillboxes with minimum side armor of 12 (or higher) from the flank or rear (where armor is even thicker). The tanks don't have sabot or HEAT, so how is this possible? Thanks.

[Griefbringer]

At close range, lucky shot with AP ammo can hit a weak spot, resulting in a bonus to the penetration.

Also, bunkers can take damage also from hits that do not penetrate, representing a lucky bullet passing though a slit and hitting somebody inside. Thus it is possible to take out bunkers with small arms fire - though it will require a whole lot of shooting.

[jivemi]

OK thanks. After rechecking the facing of bunkers and pillboxes I can count only one specific instance in which a tank indisputably did that, passing a 75mm AP (or even 37mm--they're pretty accurate) through 12 cm of pillbox armor. The other shots were probably through the front turret armor of only 4 cm (or lucky shots into the gun slit).

What threw me off was the double placement of log bunkers facing in different directions. Once an M3A5 CS blew away an adjacent bunker from the front. It then spent two turns blasting away at the side "armor" of its buddy in the same hex with little effect. At the time I was scratching my head in puzzlement, but in fact it was 'cuz that bunker faced AWAY from my armored behemoth. Simple yet obscure, eh?

Anyway sorry for the kipper. Just goes to show how easy it is to draw false conclusions before checking out the details. Thanks again and happy gaming!

[Griefbringer]

With tanks, it is in my experience to engage MG bunkers from the front, if you do not need to be particularly concerned about their return fire.

For the infantry to take out a bunker from the front with small arms fire is not particularly recommendable, since it is likely to require massive amounts of shooting and the return fire is likely to be deadly. So it is preferable to pop smokes and try to sneak up into a flanking position for close assault. Clever opponents (and scenario designers) probably try to make such outflanking manoeuvers difficult by clever placing of minefields and supporting bunkers with overlapping fields of fire.

[jivemi]

Originally Posted by Griefbringer

At close range, lucky shot with AP ammo can hit a weak spot, resulting in a bonus to the penetration.

Also, bunkers can take damage also from hits that do not penetrate, representing a lucky bullet passing though a slit and hitting somebody inside. Thus it is possible to take out bunkers with small arms fire - though it will require a whole lot of shooting.

Sorry again to resurrect an old thread, but in a Russian LC battle T-34/85s with max pen of 16 took out two pillboxes with side and rear thickness of 22 on the first or second shot. Not that I'm complaining, but it seems improbable to get "lucky" hits twice out of three. Just wondering, thanks.

[DRG]

You don't say what year or month or exactly which ammo was fired but it's certainly possible that the pen coupled with a situation where you get a bit more penetration from the shot due to random factors that this would happen.

[jivemi]

It was in Kurland, Latvia in October of '44. The armor rating for the PBs was (front, side rear):

Hull-10, 20, 22
Turret-3, 22, 24

Only one tank definitely had a side/rear shot from just adjacent; the other was behind the PB's LOS but may have hit the front from an oblique position at a couple hundred meters. Sorry didn't catch the message for either one.

Anyway no biggie. Thanks for your kind attention and prompt reply.

[DRG]

......and in Oct 44 T34/85s have limited sabot ammo that have penetration that approaches those values. As well the game has a host of random factors built in so it's NOT predictable and I'm betting if you had that turn saved from before that event then ran the turn again the next day after rebooting your computer you would not get the same results. Also, AFAIK fortification armour is not treated the same way as vehicle armour , there is a wider chance of results.

That said I will run some tests as time allows and see if anything seems off since I last tested this

[jivemi]

FWIW in a current LC battle as Germans a platoon of 5 Panthers kept blasting a couple Russian pillboxes with 30 or 40 shots each from the flank w/o effect save suppression. It wasn't 'til the Panthers got in front of them at about 6-700 meters range where the armor rating was 4/10 that the PBs finally succumbed. With flanks and rear of 18 or 20 there was no other logical way except lucky hits to get them.

So apparently my earlier experience was irregular. Cheers.

[jp10]

While it is not directly simulated in the game, the "host of other random factors" can also be envisioned to represent that even if a fired round does not penetrate a bunker wall, that wall will have taken some kind of structural stress. After repeated hits it is plausible that the protection would fail no matter the listed armor value but only as a random unpredictable event.
Which reminds of of the famous M1-1abc 90mm "Knock-Knock" round. By the late 1970s the M67 90mm recoil-less rifle was regarded as marginal in bunker busting the new generation Soviet type of defenses along the Iron Curtain. The M1-1abc round was developed as a two stage wooden projectile in a sabot. the gunner would load the M1-1abc round first, ahead of a M371A1 HE round and aim for a weak spot such as a door.
The twin wooden projectiles, being lighter would travel faster after discarding their sabot and arrive at the target before the HE round. Inside the bunker the enemy would hear "Knock Knock" and when they opened the door to see who it was the HE round would come in.