Most towns have a noise ordinance which would preclude you from firing a cannon. Where to purchase black powder Black powder may be purchased at many gun shops. In some parts of the country it can be purchased in regular department stores. You may contact a member of a reenactment group in your area. A link to many of their sites can be found by clicking here.
Black powder is a mixture of sulfur, charcoal and potassium or sodium nitrate.
A gun powder could be black powder, but it can also refer to many other chemical combinations. Black powder is sold and specified using two parameters, its weight and the size of the granules. Black powder weight is measured in different units. Modern shells have the weight listed in Drams. We sell a very nice, adjustable black powder measurer in our arsenal store.