Thank you for the information. The use of older model, but longer barrelled (and presumably somewhat higher and flater velocity) twelve pounders possibly sheds light on the deployment of Bradford's Battery. Despite its early arrival in Virginia, it did not serve with Lee's army until the seige of Petersburg. It was based, at various times, at Petersburg and Drewry's Bluff, and Hoy's history recounts at least two instances when it was placed along rivers to interfere with river traffic.
Did 1841 Model guns ever use shells, or just solid shot and cannister. Also, do you know the weight of the carriage. Are there any websites that would describe the guns, I could not find any.