.513 dia. 600 gr. RNFP

What are the chances for a 50 cal. 600 gr. bullet for long range black powder rifles? It will have to have ample lube grooves for plenty of spg or simular lube. Ideally, a 2 cavity mold, both the same profile but 1 would be a gas check version for smokeless loads. Cast at .513, it could be loaded as cast if needed or sized to .512 or .510 as necessary.

My trapdoor likes .513. The Sharps prefers .512