That US-S pointed slug with discarding petals,
and locked on base, shown above is called the
Swift 12. And correction on the weight, it is 320 gr.
And they plan on testing and maybe supplying 3.5"
versions, planning on getting around 2500 fps with
shotgun powders. I know in our 3.85" case in the long
barrel Savage, I could get over 3000 with big amounts
of our slower powders we load with.

Bought some tubing caps And here is picture
of those copper tubing caps, you can make bullet
jackets out of, and fill with lead. In picture you see
a rough one I formed with punch, and with a die they be
perfectly formed. And with right die they could be
formed with round nose with edge step for perfect roll
crimping in plastic. And on the right see big caps that
would do 4 bore.There are caps between the two sizes
that would do 8ga...Ed