I can remember flying into Laotian valleys and suddenly hearing one of these bad boys going off over the sound of our engine. A 12.7 mm DsHk shakes the world only slightly less than a 37 mm. AA gun. They were deadly accurate in the right hands and I remember a few strips of 100 mph tape over the holes in the tail of our PC-6 or O-1E. That you could hear them over the sound of the engine always amazed me.
Our only rejoice was that you couldn’t interchange our .50 cal LMG rounds with their guns.