John M. Brook wrote:
> Correct me if the information is wrong.
The "components" information for reconstructing a 12-pounder Gun canister is correct... 27 balls, a top-plate, and a baseplate. But the canister baseplate in your photo would be wrong for using in reconstructing a Canister. It is a fired one, which got re-shaped by being involved in "Double-Shotting" a cannon with two rounds of Canister. Note the seven dimples in that baseplate. Unlike some Grapeshot plates, Canister plates were not manufactured with dimples in them.
Firing one round of Canister doesn't cause the dimpling. It only happens to a Canister baseplate when two rounds are fired simultaneously from the cannon. That produces a situation where there is so much "dead weight" in front of the baseplate which faces the cannon's propellant powdercharge that firing causes that baseplate to deform somewhat, imprinting itself against the bottom layer of Canister balls.
Double-shotting could cause the cannon to explode, so it was only done in the most desperate circumstances. Thus, a double-shotted baseplate is a rare find. In my nearly 40 years of relicdigging, I've found only two. I dug both of them at a spot where the Confederates used Double-Shotted Canister to stop the massive yankee charge at Kennesaw Mountain GA. (At that same spot, I found about a dozen non-dimpled ones.)
In the 1993 Edition of the Dickey-&-George book I included a photo of a "reconstructed" round of Canister which is incorrect because it has a fired double-shotted baseplate. See photo at left on page 532.
One other piece of advice, just in case you don't already know:
A Canister's top-plate is much thinner than the baseplate. Genuine top-plates are quite scarce, because relicdiggers do not recognize them as an artillery relic. I've seen many rebuilt Canister rounds which are incorrect reconstructions because the rebuilder used two baseplates, instead of the correct thin top-plate and thick baseplate.
Regards,
Pete
