Hi S1nnerman,
I have some 10mm in 200gr Frontier plated bullets (I know you asked for hardcast), but I got a few thousand of these very cheap from Marstar some time ago, because the copper was stained. I will sell you #100 for 1cent (one cent Canadian) plus shipping, just to try. This way you get to up your trader rating, and try the bullets. I do not have any more for sale to anybody else, as I use them in my 10mm Auto Glock 20 and 40S&W Glocks, and can give you safe load data for the 10mm using slow powders and shot in 4.6" and 6" Glock barrels.
PM me if you want to "purchase" the #100 "test" bullets for 1 cent plus shipping. Also try "JetHunter" who advertises here on CGN. I have used his hard cast in some "special" reloads (450 Adams and 455 Webley) and like the product, and the service is great.
Hope this helps.
RSA1