Did in by 50 caliber machine gun from the SS168 Nautilus:
"Attack No. 2 39-47 N 142-40 E
Sight 200 ton sampan at 2329 K on September 25, 1942 and manned 50
caliber machine gun. Commenced firing at about 2000 yards using armor
piercing ammunition for 150 rounds. Subsequent ammunition was a special
belt of tracer, ball, incendiary, and armor piercing. Closed range to
200 yards by 0000, September 26, 1942, and strafed entire length of
sampan. At 0015, sampan burst into flames. Observed to sink at 0055."
50 caliber!
Fluckey's encounter with a large sampan:
"In half an hour, I welcomed Tom back aboard. Nine down, six to go. Backing clear,
we sank her with one 5 inch shell.
These single shots at the waterline from 100 yards saved a lot of ammuntiion."
Excerpt was From the book Thunder Below, page 391 paragraph 7 that was written by Admiral Eugene Fluckey the comander of USS Barb.
