That little 9-barreled contraption clamped to the bore evacuator is not a minature multple rocket launcher, it's a Hoffman device, main gun fire simulator. They used these because there was no 105mm blank round. The Hoffman charges were pretty stout pyrotechnics. I have heard they were equivalent to half a stick of dynamite. People have had fingers blown off trying to load them. Had wires running from the charge to the firing switch.