Thread: Slugs with Unique

QUOTE=Peteforskeet;If it's in a plastic wad ,plus having a bridge across the base of the slug how's it ever going to expand to bore size?[/QUOTE]

I have a Gibb 62 calibre rifle and use 20 gauge slugs in a plastic wad. This slug has a solid base but even inside a wad it expands from a loose sliding fit to deeply engrave the rifling on the wad.This is probably due to the fast ignition of black powder which in spite of the wad shortens and expands the projectile.This is one reason I believe a fast powder like 700X is used. If you pick up fired wads they show scouring from the trip down the barrel. The keyes built into the lee slug base help it expand with out collapsing.Just my opinion for what its worth.