Check Cor-Bon. For the .45 Colt, they have a 300 gr. jacketed lead soft nose that is supposed to penetrate like a solid ball before it begins to expand.

It is loaded pretty hot for the .45 Colt and is recommended for very few pistols other than Rugers.

However, I suspect they have a similar load for the .44.

It is said that it will kill any game animal found on the North American Continent.