I cast from a LEE mold a .458 pure lead bullet. It is called a 405 grain and is used in 45/70 rifles I was told. I cast then and used them in the orange Knight sabots .458 and that bullet. Out of pure lead they weigh 423 grain. And they hit with authority. In fact I used to shoot them out of an Old CVA Staghorn Magnum I had with 70 grains of powder and they were super accurate.
Then I got my White .451 rifle. so I got a sizing die and reduced them to .451. They shoot very well out of my White. But you can put that same bullet into any sabot that works and shoot them out of a .50 caliber rifle with excellent results.