--- a/data/json/items/ammo/20x66mm.json
+++ b/data/json/items/ammo/20x66mm.json
@@ -124,6 +124,7 @@
     "range": 12,
     "damage": 60,
     "recoil": 2500,
+    "loudness": 160,
     "effects": [ "COOKOFF", "SHOT", "NEVER_MISFIRES" ]
   },
   {