RAF 20mm ammunition counter indicator

[Kingscoy]

Hello everyone,

Got a question which puzzles me for a while now. I have included a pic of an instrument I have in my collection. This gauge indicates the rounds per inboard gun. The counter can be altered to set the number of rounds. It does seem to me that it was used in RAF fighters, but I have never seen a photo of an instrument panel with this indicator fitted.
Was it used in fighters or bombers? And any photo with this instrument in situ in a panel is very welcome.
Any help is appreciated!

regards,
Sander

[beaupower32]

SpitfireSpares.com - warbird Instruments


If you look about halfway down, you can find a picture of your ammo counter. From what I have found they were installed on the Spitfire (Mk III is what I have found so far) Maybe other models as well. Hope this helps some.

[Kingscoy]

Yep, I know that site...but the man running it didn't know it either if it was used in fighters or bombers or both. The text on the gauge itself does point in the direction of fighter use....but that is still my own assumption....So I'm afraid that the question remains. But thanks for your reply!!

regards,
Sander

[Johnny .45]

This is just a guess, but the writing on it suggests (to me) that it was intended to be used but the loaders. Again, just a guess, but I'm thinking that rather than actually "count" the ammo left in the magazine, it uses clockwork, i.e. it begins to countdown the moment the firing button is pushed, since they know the firing rate of a 20mm Hispano cannon, and stops when the button is released. Although it wouldn't work well if you didn't release the trigger when a gun jammed, it would give you an idea as the the minimum ammo left.
As for what plane it might have come from, the "inboard" and "outboard" would suggest to me a 4-cannon plane, like a Spitfire or Hurricane with the "C" wing. I don't know if they could just ignore the "outboard" markings with the planes with only 2 20mm's and 4 .303cals, or use a different counter. The Typhoon was also a 4-gun plane. To complicate things, "inboard/outboard" doesn't necessarily mean wing-mounted guns...the same terms are used with nose mounted guns like the Beaufughter and Mosquito have. I'll keep an eye out. The sight that beaupower32 mentioned also has a very similar .303 counter, but that only says "Set For One Gun", which I would guess means that all the guns hold the same amount of ammo. I noticed that it seems to be less grungy around 400 rounds, which I think is the number each gun in the Spitfire holds. I dunno...good luck. My feeling is that it's from a multi-engine plane, but that's just a pure hunch.

[Glider]

300 RPG seems a lot for a 20mm. I thought most single seat RAF fighters held up to 150 rpg which might indicate a twin aircraft.

[Colin1]

I thought most single seat RAF fighters held up to 150 rpg which might indicate a twin aircraft

That seems closer to the mark for me, I thought it was 120 rpg once they got belt feed sorted out

[Kingscoy]

Thanks for your replies! I still didn't find any fighter cockpit photo with this instrument in place so the possibilty that it was used in Beaufighters, Mossies and such a/c types could well be it. I will dive into that direction to see if I can find a pic.

Thanks again!

Regards,
Sander