Since the panic, they are very rare. No one I know of "has em just out for sale". They were relatively scarce BEFORE the panic. Other than some scalper on Gunbroker trying to squeeze every dime out you for 'em, sorry.
Barnes does make a all copper bullet (and solid), their Banded Solid line. They are a tough bullet and will play heck on what you want to mangle up, albeit, the bullet has a very wide metplat (so it isn't going to be a super long range rifle bullet).
Back during the 1st Gulf War, I saw some 30cal (bullets only) in 165 BTSP made out of depleted uranium. Pretty cool stuff, and yes they were armor piercing. Oh yeah, the only people I knew who had them were soldiers. Man, that was 20 years ago, and I wasn't as into guns then as I am now. I didn't know what I was looking at. I guess they were a cousin to the depleted uranium shells used in the tanks.