Possibly influence the UK - especially if it proves as robust as it the MAS49/56 and if the plans and some of the plans and possibly jigs made it to the UK
.303 or 7.7x56mm rimmed is 78.11 mm (3.075 in) over all length -
7.5 x 57mm mas mod 1924 is 76.00 mm (2.992 in)
(Mauser 7.92 x 57mm is 82.00 mm (3.228 in) )
I'll tell you who it would influence - the Germans
They struggled to make a decent SLR early war and might just keep the rifle in production - were was the main production for the French Rifles?
Paris?
What's ironic is the Germans captured the intact production lines and prototypes, examined them, and then did nothing with it.
The factory that designed and made it was MAS, based in Saint Etienne:
en.wikipedia.org
In what was to become Vichy territory:
en.wikipedia.org
I wonder if the Germans are the more likely to pick up the MAS-40 after the Armistice, and really after Op. Attila. Basically seize and use all the guns and ammo themselves. They would have seen first hand how effective the gun was. It would complicate their already tangled logistics train, but there would be a real gain.
They also would like to seize as many of the tools and dies as possible. How big of a re-engineering project would it be to chamber the gun for the 7.92 round the Germans used elsewhere?
Would the British be of two minds on this weapon? Meaning that the soldiers in the field could appreciate it's great utility; but the leaders back home noting that it didn't alter the outcome of the Battle of France and we have all of these SMLE's that work so well, and twenty mega-tons of .303 ammo.
I doubt they'd want to mix up their logistics any more than they already were. Though with firsthand combat experience who knows. The SVT-40 made a pretty big impact on them, which resulted in the ripped off G43 rifle.
I'm not sure how much it would really take to reengineer them, but the French and German cartridges were significantly different; it wasn't just length, the French case was also wider. So they'd have to both rechamber then and switch out the barrel. I think the cartridge pressures were roughly the same, but the Germans used only their heavy 198 grain bullet from 1933 on for rifles, because out of the shorter 24 inch barrels of the K98k (the MAS40 used a 22 inch barrel) the flat base 154 grain bullet produced too much of a fireball and noise at the muzzle because the extra gun powder in the smaller bullet version of the cartridge didn't burn off in time, as it was designed to work in the 30 inch barrel Gewehr 98. The French used the 'balle C' flat base 140 grain bullets for rifles and reserved the long heavy boat tailed bullets for MGs. So I'd imagine that the Germans would have reengineer the French guns pretty significantly to get them to work with German ammo. However this was actually done with a very similar rifle which also used the gas impingement system:
en.wikipedia.org
The
Hakim Rifle is a gas operated
semi-automatic rifle. It was originally designed by Sweden and produced as the
Ag m/42 for the
Swedish Army. The tooling and design were later sold to Egypt, and the Hakim was produced there during the 1950s and early 1960s.
While the Ag m/42 fired the
6.5×55mm cartridge, Egypt owned large stockpiles of
8×57mm Mauser ammunition, much of it left behind from World War II. To take advantage of the large stockpile, the Hakim was further re-engineered to accept the larger cartridge, which also necessitated the addition of a permanent, non removable
muzzle brake to help reduce the concurrent greater recoil.
[4]
The French 7.5mm cartridge case had about the same dimensions as the Swedish 6.5.
Also apparently the Hakim used the heavy 198 grain bullet ammo, so with the muzzle brake it could work very well.
The problem for the Brits is that they need a lot more weapons ASAP and developing a new semi-auto rifle in 1940 is not a priority. Maybe if it were ready by 1942 they'd have enough breathing room to do so, but since the SLEM-1 wasn't ready then and the designer didn't pick it back up until 1943 after evacuating in 1940 from Belgium that wasn't in the cards IOTL. But then he didn't really have the impetus to do so until the British asked for it.
en.wikipedia.org
Part of the issue was the British waiting to decide on 7.92 Mauser (already in production for the Besa MG) as their future ammo (until the infantry board decided in 1946 to make the .280). I suppose had the British decided earlier on what they wanted they could have made it work and then banked on capturing stockpiles of German ammo (which they did quite a bit of in Africa and Italy IIRC) to make up for their limited domestic production of that type. I think it would be very doable for them if they wanted to, the issue is making them want to. I thought having the French get it in service and the Brits seeing the advantage it gave, plus it's reliability and ease of maintenance would help push them along that path even if they have to use 7.92 Mauser for it.
