Melonfish,The Gustav,and its sister gun were the biggest gun's ever mounted on rails(and needed a crew of thousands, took part in the seige of sevastapol, managing to destroy bunkers which were feet thick concrete and under metres of water iirc think it was 800mm or about 32in calibre alot bigger than any battleship gun, which i think was the Japanese Yamato which had a 18 inch(i think) gun so dwarfed by comparison,shell weight was approx 4800kgs. That should manage to stun most wasp's even the one in Jonathan D last pic.