I need a load for #4 buckshot for a 2 3/4 inch 20 ga shell using either Unique or Herco. I believe you get like 12 pellets in a 2 3/4 shell?

The following load is published in the 3rd edition of Reloading for Shotguns;

20g 2 3/4" shells
Federal Plastic Hi Power case
18 count of #4 buckshot
Federal 209 primer
Rem SP20 wad
19.0grs Herco powder
1275fps
11,000 psi

Another load published for exactly the same components as above only using 25.0grs Blue Dot for same 1275fps at 9,500 psi.

Thank you sir.