Current in game I-16 types

[Pursuivant]

There are both Type 24 and Type 24 (SPB) variants.

AFAIK, all Type 24 had 4 ShKAS MG. The nearest Type 24 variant with cannons is the Type 28.

My guess is that rocket rails were added as field mods or factory refits after 1941, once I-16 started to be repurposed as ground attack aircraft. It would be a very easy refit to do, and I get the sense that the Soviets added rocket rails to anything that would fly. But, officially, the Type 5 and Type 6 didn't have rails as built.