Two sets of Antique Ordinance plans from Dixie Gun Works just came in the mail. I picked up the 24 Pdr. Coehorn Mortar and 12 Pdr. Mountain Howitzer plans. Anyone interested in building cannons should look into Antique Ordinance. There is a wealth of information that would take a considerable amount of research to get. At $10 plus shipping they are well worth the price. They could get $30-$40 easily for plans of this quality.
Ive built a golf ball caliber Coehorn but my next project will be a 1/2 ish scale Coehorn and I wanted something that was closer to scale. After I get that done I will tackle a 1/3 to 1/2 scale mountain howitzer. The carriage will be a new challenge.