WW1 37mm Knowledge required !!

[Tony Williams]

So a few side by side images would help clear this up and does any one know where a surviving Maxim is ?

If you mean the light Mk III / V firing 37 x 69R ammo, I don't know of any survivors. I used to visit the old MoD Pattern Room (now relocated to Leeds) where they had some interesting kit including a Vickers 1 inch aircraft gun from WW1, a 37mm COW gun, and a 40mm Vickers Crayford, but I didn't see a light Maxim there.

 

[ammofo]

"Gspragge" - You have made a great observation regarding the 'blunted' projectiles. See attached photo which clearly shows that the tips have been filed/ground and have many facets rather than an evenly machined point. This is yet further evidence that there was much tinkering with existing components in order to cobble together a solution to arming those 'new-fangled aeroplane thingies'. (I had already noticed the ground noses on these rounds but didn't attach the relevant significance to it due to my inferior knowledge !!... I think you've cracked it.
Any ideas as to whether they were for French or British planes?? - I think that's the only unsolved aspect now !!

 

[Gspragge]

Here is the difference between an unmodified Mle 1892 and typical short 1pr with 131 fuze. It's not much
but enough to cause a jam or feed issue. I get 70mm from the bottom of the band to tip on the M92
and 67mm on the short 1pr. How long are your projectiles in this respect. I think the modified projectiles
were for the MKlll Maxim, and there may have been a French trial or at least French projectiles were
obtained as perhaps more easily modified than British 1pr types. Who used or tried what could remain a mystery.
The unmodified length projectiles are perhaps for French use, though there is no reason they couldn't have been tried out in
a regular 1pr Maxim. Questions Questions ! Without actual reports on the trials and so on we may never know.
It is worth noting that the Phosphorus shortened 1pr for the MKlll Maxim was also a regular AP pointed projectile
that has been ground down like these (there is a thread on those somewhere on site).
We are calling these incendiary projectiles, but maybe the intent was for a viable tracer like the Germans had
in service ?

 

[ammofo]

The blunt rounds are 67mm and 66mm - the variation again pointing to post-production tinkering.
I'm open to the tracer possibility (rather than incendiary) though the tracer would only really be useful in a belt/clip to allow continuous fire, but that applies to the Mark III anyway.

 

[Tony Williams]

We are calling these incendiary projectiles, but maybe the intent was for a viable tracer like the Germans had
in service ?

In the WW1 era incendiaries were made which burned throughout their flight, and therefore did dual duty as incendiary/tracers. For example, the .303 Incendiary B Mk IV, which was still in service in WW2, was based on the Buckingham of WW1. This was regarded as a "day tracer" as it left a smoke trail.

The primary purpose for the large-calibre incendiaries in WW1 was to engage airships and artillery-spotter balloons. It was better to have them burn throughout their flight to provide the maximum opportunity for the flame to set light to gas outside the envelope.

 

[ammofo]

Two functions are always going to be better than one, so incendiary & tracer makes perfect sense. Makes you wonder whether these rounds would have been interspersed with the flat-headed No131 fuse rounds / or vice-versa...or whether they were considered a good enough 'stand alone' round for dealing with Zeppelins etc. It sounds as though they probably didn't get much opportunity to experiment with them before they were withdrawn.