Here is a novel slug idea, hard plastic support ring on
the front, and a locked base ring/seal. Metal never
touches the bores. Work in great rifled and good in
smooth barrels. These are steel, lead/copper would do
great also.Could be made heavier and different points.
Flat point shown would do great damage to game.
On the net- ammunitiontogo.com
This one is about 500 gr.

Second picture is the 499HE to use in redoing the 500S&W,
shown on the also, in single shots, etc,for those wanting
much more power at 40-50% lower pressures.Ed