lee drive key slugs , one more time 

Actually when using those one piece wads, you want the cup and pedals to come free of the slug after leaving the barrel.

Oven wax paper.

Not sure why you’re powder coating the slugs. They’ll never contact the barrel while they’re inside the wad. Also find the right wad for your hull and you won’t need a nitro card.

interesting for sure i will be folling this for sure i have not reloaded shot shells in years and never reloaded slugs now i did make some hot melt glue slugs from the directions of a state warden to test, He used them to drive bear away from peoples bird feeders. I can tell you from my 20 yard testing they might be deadly they would go through a 1/2 inch piece of ply wood i also fooled with glued bird shot also very deadly a 20 yards of course no accuarcy.