Nitro Cards were originally used by black powder shotgunners to seal between the powder and the shot. Today they are used as a fine-tuning spacer wad inside the shotcup. Use 12 gauge in a 10 gauge shotcup and 20 gauge in a 12 gauge shotcup. .125" Thick.
- Nitro cards are used as a seal between the powder and the shot.
- They can be added to any modern load where the shotcup is sitting too low for a proper crimp.