Nope.
North American B-25H "The B-25H was an improved version of the B-25G. The fixed nose armament was increased to four nose-mounted .50-cal. machine guns and four more .50-cal. machine guns in fuselage mounted pods. The 75mm cannon was changed from the -G model's M4 to the lighter T13E1 75mm cannon. The top turret was moved to the forward fuselage and the lower turret was removed and replaced by a single .50-cal. machine gun in each of the two waist positions. A tail turret housing a pair of .50-cal. machine guns was added bringing the firepower total to 14 .50-cal. machine guns and a 75mm cannon. The aircraft could also carry up to 3,200 pounds of bombs."
No 20 mm.
Modified J's? Same Source:
"NAA modified 800 -J models by installing a solid nose in place of the bombardier's 'greenhouse.' The solid nose housed eight .50-cal. machine guns bringing the total to eighteen--fourteen of which were forward firing for strafing missions."
