bullets

[bruce moulds]

i do not have a slug gun, but admire this type of shooting greatly.
i understand how these guns are loaded and why, but have always wondered this.
how much less accuracy is obtained if a bullet patched to bore diameter is used as in bpcr? thinking a well sealing wad between powder and bullet would be useful here.
also, did doc pardee use bore or groove diameter bullets, and were they gg or pp?
keep safe,
bruce moulds.