Just a note for you historians....purely anecdotal of course.

The 345th Air Apaches flew B-25 C models with 8 forward firing fifties early in the war during the New Guinea campaign.
Four .50's were mounted in the nose and 4 more in two blisters on each side of the cockpit. These were "field mods", not factory, initially. American ingenuity at work; they needed to suppress the flak guns when bombing airfields.
The "strafer nose" with 8 .50's came along after that and some were modified "in the field" in New Guinea, some in Australia and in the US as well.
There were lots of other armament experiments as well. One thing they tried was mounting 8 more .30 cal MG in the bomb bay. They were racked 4 to a side and hung at a 45 degree angle. The bomb bay doors were opened and the guns were fired as the plane flew across an enemy airfield. So these "flak supressors" led the squadron and hit the field with 8 .50's and 8. 30's. This mod didn't catch on, however and was not pursued.
Just a little anecdotal info....from my father, a guy who "went there, did that"...and flew a C model with 8 forward firing .50's., 4 nose/4 blister.