the plate i have is mild steel and has been hit with 50.bmg lead core multiple times. not even close to penetrating (less than 1/4 of an inch deep).
i have been more impressed with the penetration from 3006 lead core which almost looks just as deep.. it really surprised me.
Lead bullets of any kind won't do much to a steel plate unless it's got some kind of steel jacket and the plate is held quite strongly, like if it's fixed to a cinder block.
Most AP are some kind of tungsten alloy core, which is both hard AF and expensive AF. Those tungsten alloys are about the same as the tungsten alloys used to make dremel bits that can cut through hardened high-carbon steel. These bullets tends to punch a tiny hole just their own size into anything (that's why they're absolutely the worst thing to use for hunting; you're almost sure that the bullet will go through and not expand in the animal). When they go through an homogeneous substance like a metal plate, the hole left almost looks like a perfectly drilled hole, with nothing bent around it.
A tiny 5.56 will pierce through 1/2 inch or armored steel, so I'm almost certain all the calibres you wanna try would pierce through your 1'' steel plate if it's mild enough, with maybe the exception of the 7.62x39, which is barely more energetic than the 5.56.
Black tips .50 bmg will go through the armor of an APC and its engine block, stopping the APC right in its track. I've seen a british soldier stop an iraqui apc with a single shot of .50 (using a barret) in the engine at a distance of about a km. It went through the armor making a hole just big enough for itself, then ruined the engine, stopping the APC like the engine had been turned off. So if you somehow put your hand on some .50 black tip, be very careful to place a boatload of sand or anything that will absorb energy behind it, not just a couple of cinder block, cause these bullets don't behave like we're used too with our normal lead core. They will go forward and forward until all their kinetic energy is dissipated, and they don't lose that much of it when they hit something if they go through it.
APs are probably not for sale anywhere in canada in the civilian market for obvious reasons, so I doubt you'll get your hands on any, but if you really want to see some in action, a trip south of the border is probably the best way. Other then that, the CF are always looking for recruits...