Best source of information on slug guns

[Plastikosmd]

Gun is a 1860 something Pierce, a contemporary of billinghurst I was told.
The pins were for some form of loader, not really sure. My other mechanical loaders work off of false muzzle pins.

Those are oxidized lead slugs, not paper patch, rather it is a cross patch gun.

Alloy, as I was told was 1:20 lead tin, rear is pure lead.

The gun was also shot at 600 yard match at camp Pendleton

Not sure if gun was shot by both Lester or Clyde hill who took second and first respectively. Nevertheless, the gun did well. Both guys played a role in developing the slug for this gun. Sigh, I was born in the wrong age