Max,
As Tim mentioned, be very careful with the hardness of Dixie slugs. First off, these are 3" slugs and unless your gun is a rare magnum type, I am sure it is a 2.5" Holland specifies 16 to 1. Dixie is talking about"bullet alloy" whatever that is , and heat treated which is extremely hard in most cases. If you bulge your gun at the muzzle, it is over! I would shoot something less than a .735 myself. Bullet velocity is generally about 1500 - 1100 with slightly higher for nitro.
Accuracy, my best, is about 1.5" groups at 50 yards. Many factors influence what acuuracy you get and unfortnatley it is a trial and error deal. Loading these is very straight forward. Note that the wadding will play a critical role in addition to bullet size.
I have two guns, a 12 and 10 made within a year or two of yours. I would seriously rethink shooting a bullet as hard as described. Remember your not tlaking about an 870, put a fine vintage gun.
JAZ
