Black Powder Black Powder Both cannons in action together. All testing and tweaking (of loads, ammunition, sighting, etc) is done on the OSSR&PC range. 126667881 The one-third size replica, ship's cannons belong to 2 enthusiastic OSSR&PC members, They were built to scale by an OSSR&PC member (and engineer). The internal breach and barrel configuration was lifted from engineering drawings of circa 1800. The barrels are deliberately over-engineered (for safety) and made from laminated steel. 126667882 127251221