He is Dominick Carpenter and did you send an email to the address in his post above?
I dunno, it worked for me. In my opinion, filler isn't necessary.Now the question of filler;
AAA states "recommend a filler of a weight equal to the weight of a standard iron round ball". How might I determine the weight of a standard iron round ball 2 and 1/2 inches in diameter? Charts provided are for bores "less than 2 inches". When I attempt to use the "Spherical Shot Weight Calculator" I am told "NaN" which I am guessing means not available.