Does Cast Bullet Hardness change after Powder Coating?

A four-minute video investigating the effects of the heated 'Shake & Bake' method on cast bullet hardness.

All the bullets in this experiment were cast two weeks ago in the same session using the same mould and alloy.

Bullets were powder coated using Emerald Coatings' Flat Black at 400F for 15 minutes using a standard toaster oven.