Armoured panel ID.

[Daan Kemp]

That's interesting, it's the only inch thick plate I've found, I can't say I've ever fired ball ammunition against steel, but I am surprised it will penetrate approximately half way through one inch thick steel?

I assumed standard ball would simply put a small dish into thick steel plate.

The composition of the steel determines the penetration. Ordinary steel is relatively soft and needs treatment to be hole resistant = armour. Thus shooting plates on a range means the plates have to be a specific steel, otherwise they crater and look like these plates quickly.

Eg in the army we used to shoot falling plates at 100m with the R1 and 303. No problem with holes or craters.
Changing to 5.56 and R4. My first experience with nromal 5.56 ball was that it was useless as the plates didn't fall over. On inspection I found nicely centred holes in the plates, didn't transfer the enercy at all. We changed the steel of the plates to accommodate the new cartridge. Not thicker steel, just better.