10 gauge slug diameter?

[SND]

Would any of you happen to know the size diameter for 10 gauge slugs, if one was to make a mold for it? I know nominal bore is .770, but I'd like to know the size to make it for easy reloading, just so it slips in the shell and can be held in there. I'm thinking .75" will probably do it but an exact size that would be snug in the shell would be great.

Thank you very much for any input/help.

 

[LUTNIT]

Full bore slug for a rifled barrel or slug for a smooth bore? Is there any choke?
There would be a large range of sizes possible just like how 12ga range from .685" to .735".

For a smoothbore I would go 10-20 thousands under bore diameter. Since bore diameter is .775" I would go perhaps .760" though .750" would also work. For a rifled barrel I would go with .780". Are you dropping it over a fibre wad or putting it in a shot cup? I get excellent results with wad slugs and they prevent barrel leading but they have to be smaller. Measure a bunch of difference wad pedal thicknesses, subtract twice that (for each side) from the bore diameter, and maybe a few more thou.

My opinion:
Full bore: slug the barrel and add 2 thou or so
Over a fibre wad: bore diameter - 10 thou
In a shot cup wad: bore diameter - single pedal thickness - single pedal thickness - 5 thou