There's no question that the Spit Vb was still using the drum magazines. I'll scan a photo that shows a frontline Spit Vb being serviced and you can see the mechanic holding the drum magazine. Based on the camo scheme it is definately post August 15, 1941.
I remember Pierre Closterman in his book the Big Show, complaining about the switch back to the Spit Vb when he joined 602 Squadron, after flying Spit IXs with 341 Squadron. The comment was very specific to the ammo load of only 60 rounds, less then half of what the IX held, and this was in 1943 when he joined 602.
The Spit Vc entered service in October 41, so I suppose the Vb's already in service just soldiered on. I know that the jamming problems of the Ib and IIb were cured by the time of the Vb but I thought that was in the adjusting of the mounting of the cannons.
It occurs to me that it's possible the first of the belt fed cannons went to the Hurri IIc. It has the smaller wing bulges that would cover the feed unit and the larger wing that allowed for the twin cannon installation, may have been easier to modify quicker for the belt fed set up. The Typhoon clearly had that set up too, although that was later.
The C wing of the Spit was a major internal redesign and may have taken that much longer to get into production to allow for the belt fed. Nothing anywhere shows me a Vb with anything but a drum fed cannon. And the Spit V manual makes no mention of belt fed with the Vb and it's the last updated version that includes the Seafire variants of the Spit V.
Added the image of the Spit Vb with the ground crewman holding the drum mag. As the Spit Vb has the yellow leading edge, it dates the photo post August 15, 1941 and because it still has the early war fuselage roundel, pre May 15, 1942.
Dan/Slack
