agree with the use of blackhorn, i used imr pellets, and loose pyrodex with my optima and barnes mx, after 3 shots with either, those sabots were a bear to get down the barrel, another consideration is no so much the fouling the length of the barrel, but you can develop a crud ring, which can give a false "feel" the bullet being completely seated when its not. since using black horn no crud ring and easier loading even after 10 shots