I had a look through my notes and found a picture showing ammo being loaded into the guns of a Hurricane IIB.
Looking at the picture, the gun positions are staggered to accomodate the individual ammuntion boxes, also the ammo boxes for the outer two guns seem to be mounted more forward than the wing’s inner four.
The flash eliminator adds approximately 4″ to the overall length of Browning .303 machine gun.
Regards,