.45 super brass can be loaded up to .450 SMC with a fully supported barrel and comp. I have a ported barrel on mine (see pick above) and easily pushed 1,325 fps with cast bullets which is right in .450 SMC territory. The SMC is basically just a .45 super+p. And the .460 Rowland is a .450 SMC+p. Since .45 super brass is made to .460 Rowland specs, I don't see the need for the SMC. you will however, probably need a compensated barrel to slow the slide down at those power levels.