I found this regarding the bomb configuration:
and here says 3 7.7 machine guns:
Wich is explained by this configuration:
-1 12.7 on the dorsal (350 rounds)
-1 7.7 on the belly (500 rounds)
-1 7.7 on the right side (500 rounds)
-1 7.7 on the left side (500 rounds)
Same source:
