I didn't realise that the Soviet Union had any B-25G's.
Just few aircraft, books inform about 8 aircraft transferred to the VVS VMF, I'm not sure if there were any more. It looks like delivery of few (8? 10?) aircraft for test purposes.
What I don't understand is why they would use such normally extremely heavily-armed aircraft (it had the 75mm cannon in the nose) for a reconnaissance aircraft. It would seem that a glass-nosed version would be more appropriate. These aeroplanes with the cannon would seem particularly suited for anti-shipping activities, which the Americans used them for in the Pacific.
Because all B-25s were operated by ADD units, first two B-25G were delivered there too. After few test flight and combat missions it was clear that this variant is unsuitable for long range bomber units. All B-25Gs were delivered to naval aviation:
? 2 - 118th OMRAP of VVS Northern Fleet, delivered in 1944;
? 2 - 15th OMRAP of VVS Baltic Fleet, first combat missions in November 1944;
? 1 - 14th Mixed Air Unit of VVS Pacific Fleet, delivered in the end of 1944, soon transferred to the 50th OMRAP of VVS Pacific Fleet;
? 1 - 2nd Mine-Torpedo Air Division of VVS Pacific Fleet.
Do you know if the Soviets used any B-25H's?
I've found following variants:
? B-25B, 40-2242 - interned after raid over Tokio, transferred to Moscow to 65th Special Air Regiment (65-й авиационный полк особого назначения)
? B-25C
? B-25D
? B-25DP - this is Soviet designation of B-25D-30
? B-25G
? B-25J
From 870 assigned 861 were delivered. It seems there were no B-25H, but in mentioned website with Kotelnikov's article I've found following info:
Во 2-м гвардейском полку B-25J с дополнительными пулеметами использовали для ночных штурмовых ударов по аэродромам противника.If my Russian is correct, it means:
In 2nd Guard Regiment B-25Js with additional machine guns were used for nighttime assaults against the enemy airfields.I'm not sure what "additional machine guns" mean in this case.
Possibly they got used for other tasks if the VVS did not like the 75mm cannon, took that out and used the airframes for other purposes? I'm just theorising here.
In fact cannons were removed in case of two B-25Gs used in 65th Regiment for transport duties post-war. I guess that two other used in "Щука" trials had gun removed too. But during WWII B-25Gs had cannons installed and used in combat.