I know some .50 Cal BMG will do that, but what are some other cartridges ?Also, are all steel plate the same hardness ?
Steel plate and steel plate armour are two different grades of steel, and normally nearly anything will go through steel plate. Chetak
At what range and angle of impact? And is this mild steel plate or armor plate and if it is armor plate is it cemented, face-hardened or RHA? What Brinell hardness is it?
I'd place my bet on a 155mm though you can't go wrong with the 8 inch. All steel plates are not necessarily same strength. It all depends on the molecular make up of each steel plate. Some can be strengthened and others are somewhat weaker.
You need to read in depth about steel and the many forms and recipes that can be used as well as the difference of a sabot and a FMJ round. Many factors can change the ability of a given object to resist a projectile. Angle being top of the list. Next time you walk past a Bank look at the BR window, if they have one, and note it is angled down from top to bottom. This adds to the rated strength and deflects most rounds in a direction that may assist in the round not bouncing around and hitting others in vital locations. Modern armor used on tanks includes DU. My former employer has steel that at 1/2 is as resistant to attack as 1 of the competion. There are other tricks like adding ball bearings or metal shaving to steel and cement ot break tools used to drill. They will have an effect on the ability to break a projectile as well. You are just one more looking for a short answer to a very complex issue. Armor piercing rounds have been around for some time. Sabots and DU. A .50 sabot armor piercing round may well penetrate what a standard .50BMG will not. Silk can be effective in stopping a projectile too.....you might need a thick blanket wrap.
