Bit of deja vous here, we had a similar thread a while ago, never mind!
In the 1970s there was a real field gun outside the Odiham officers' mess. NAAFI bean cans (full ones, mind) were a very good fit down the barrel. A "spare" thunderflash was often found to send the beans on their way during happy hour. Fortunately, the gun was always aimed
across the airfield because one day, OC Ops's dog, being taken out for its walk, found more than a few singed and battered cans about a half a mile away. Had the thing been aimed inboard on the domestic site it could have "bean" chaos. After that the spoilsports had a plate welded over the muzzle.
Never forget the night of our CFS course graduation. George McCracken shot the entire wooden pelmet, curtain rails, new curtains and a few kilos of barely dry plaster off the wall in the newly decorated Ladies room at Shawbury with the Navy's cannon. "Totally innocent accident, m'lud, of course".... True, he was aiming about twelve feet lower at a stack of pint pots on the back of an upturned armchair and missed.
