I have to assume that machine guns dominate the “small arms” number. I think it’s worth noting how many countries focused on getting newer better machine guns in the interwar period and went into WW2 with basically the same rifles they had in 1918.
Yeah probably. Intermediate cartridges would improve MGs quite a bit though by improving mobility, allowing for less heat build up, lower recoil, allowing for lighter weapons, and allowing for more ammo to be carried. Especially with extended firing having more ammo and less heat build up is pretty huge, not to mention helping keep things less expensive.
But in terms of the interwar-WW2 rifles that was a function of cost. Everyone wanted semi-auto rifles, but very few could afford them, so they went the cheaper route and developed new, cheaper, and lighter MGs that were more reliable. The US was the outlier there, though they did try and modernize the older models with mixed results.
I'm just surprised no one (other than the US) didn't realize the value of an intermediate cartridge given the extensive operations research does during and after WW1. I guess that was an expense thing given that the assumption that it was either develop a new smaller caliber to gain the advantages from that rather than simply shortening the existing cartridges to gain a partial benefit or keep what they had to use all the WW1 stockpiles. I suppose the allure of the advantages of the caliber shift were so much that most militaries considered it pointless to do anything but that, but since they couldn't afford it just to stick to what they had because rearmament cost too much otherwise.
I'm not sure about the French, but it seems like everyone else was interested in a 7mm caliber shift, with the exceptions being Russia, which looked at the 6.5mm thanks to Fedorov, and all the other states that already had 6.5mm and considered moving up. Italy was the only one who tried with their 7.35mm cartridge for rifles, which was basically an intermediate caliber in power, barely more powerful than the 7.62x39:
en.wikipedia.org
I just don't get why they didn't try to upgrade the 6.5mm bullet, it would have been so much cheaper and easier to work with what they already had. Maybe a flawed understanding of 'stopping power'?