For a number of years I made my own jacketed bullets in .25 caliber and .22 caliber. Shot them in a .25-06 and a .222. Bought swaging dies and a swaging press. Bought blank jackets made of drawn gilding metal. I have a Lyman mold that makes a slug that looks like a piece of lead wire. The mold has a screw adjustable bottom in it allowing one to make a core that weighs from a very few grains to something over a hundred grains. This lead core, made of soft lead, was then swaged into the jacket making a jacketed bullet.
As to putting a jacket on a bullet made to be shot as cast, I don't see the point, and so far as I know, nobody makes equipment to do it.
There's one exception. You can buy shotgun plastic sabots made to seat a cast lead slug into, which makes your shotgun a slug gun. They work great.
