Tinker, IIRC the gun weighs 7#8oz. Don't have the barrel weight. I have tried Blue Dot, and find it difficult to light up. I got a 12 bore recipe from Ross Seyfreid using unique which is truly great, so will try to stick close to that. 600 gr of Fosbery sounds very close to right, as the 12's use 750 gr bullets. I may have Steve Brooks make a hollow point mould at 600, with a blank pin to cast solid at 40-50 gr more- still considering.
Thanks all for the advise! Doug