20 gauge howdah ballistics?

[DutchmanDick]

Anybody who owns a 20 gauge Pedersoli or Middlesex howdah pistol - have you chronographed your guns using .600 ball loads? If so, what powder loading did you use? I'm trying to find out what sort of m/v I can expect with a 350 grain .600 ball and 60 grains FFg from a 7-1/2" barrel, and I don't have access to a chronograph.

 

[Jaymo]

I don't know what velocity you'll get, but my .61 caliber round balls cast from wheelweight, propelled by 48 grains of fff sure blow through a 55 gallon drum like nobody's business. Also has a healthy kick.