Found this in the diary of Pvt. John Walters. John served in the Norfolk Light Artillery Blues. This was contained in his entry of April 3, 1865. This refers to the action at Rives Salient near the Boydton plank road west of Petersburg the previous day.
"Today, I came up with that portion of our company who had charge of the mortars in the rear of the main line at Petersburg. They all came out safe and must have done well, as after firing til the friction primers were exhausted, they fired some sixty rounds more by heating the priming wires (gimlets) red hot and then inserting them in the vents. No better evidence than this is required to show that they did their duty."
Dan