Or they could have done what the, Czechs and other smart nations did. Gone Tedesco and "borrowed" a working caliber and then borrowed the "guns" that went with it.
The Italian air force was familiar with Mister Browning. No reason the Esercito could not have "adopted" the same results.
Either would have worked
Now we come to the 7.7 mm rifle AND MACHINE GUN problem. You will notice that the Japanese, like the Italians and THE GERMANS, did not adopt cross service commonality like the Americans and to a lesser extent the British did with infantry and aircraft weapons?
The Germans had the same calibers for the Luftwaffe and Heer...and Kriegsmarine.
The Esercito is fighting in North Africa. They need a bullet that will carry for the machine gun line and punch into engine blocks to ruin trucks as well as men. Go big or stay home.
A well designed 6.5mm bullet will do that (see Swedish sniper bullet, later adopted as the standard bullet for the army, good for 1000m sniper competitions). In fact the historical 6.5mm Carcano bullet had better penetration than the 7.35mm bullet adopted. LMGs though generally don't need to shoot out to 1000m, save that for the MMGs/HMGs, which could use 8mm Mauser if needed. The 140 grain Swedish sniper bullet as a model for the Carcano cartridge would be lighter than the standard Italian round nose bullet, but with much better ballistics and faster, so therefore flatter, due to the lighter weight. It would punch through a vehicle body at normal infantry combat ranges, while it would certainly penetrate far enough into an engine block to stop it.
There it is... North Africa. What works? (^^^)
Not spreading themselves too thin by going into Russia, per my previous thread that saves thousands of trucks, dozens of aircraft, lots of various guns, and supplies.
One of the things about Italy's army that has always boggled my mind is the Breda 37.
Why is it that the infantry are fighting in the desert with a ridiculously heavy gun that feeds from a Hotchkiss-esque ammo strip (for all your fouling needs), while a significantly lighter machine gun which fed from enclosed detachable box mags is exclusively used for the bow MGs of tanks? Also why does it's tripod weigh as much as the gun?
Actually why use either when the belt fed Fiat–Revelli Modello 1935 exists and could probably be easily upgraded? Or why not a SAFAT in 8mm Breda? Hell the Italian army actually did use a hand full of SAFATs. Actually, since this is supposed to be a heavy MG, why not go the full 9 yards and just skip 8mm Breda all together in favour of widespread use of 12.7mm SAFATs?
If you can ever figure out Italian military 'logic' with the above, let the rest of us know.
Speaking of the S.M. 81, it was one of the earliest bombers that I think had the speed and payload to make skip bombing useful. Had the Italians invented this technique and invested in the training required, they could do some serious damage to British shipping without the expense of torpedoes.
The fact that the Italians didn’t develop naval aviation further was another failure. The Germans failed to do that, but it was understandable given their focus on land warfare. Had the Italians developed a four engine B-17 class bomber for the navy, it would benefit not only them but possibly help Germany win the war on the Atlantic convoys.
The Luftwaffe did develop a specialist anti-shipping unit pre-war and in fact used them in the Spanish civil war. Part of the issue is that the German navy jealously guarded access to things like an aerial torpedo and their experienced naval flyers, who in turn were confined to just using flying boats, but there was very effective Luftwaffe anti-shipping units in WW2:
https://en.wikipedia.org/wiki/10th_Air_Corps
They were in fact used extensively in the Mediterranean.
Plus there as the dedicated Atlantic anti-shipping units:
https://en.wikipedia.org/wiki/Fliegerführer_Atlantik
I am still not sure on the Squad / platoon level LMG - In think the best choice would be the MG 34, but the weapon design was a state secret in Germany so unlikely to be shared with Italy - certainly not in a timely fashion.
Therefore next best would be the ZB30 LMG (effectively the Bren gun)
The MG34 was too difficult to make, so the Germans designed the MG42, which was initiated in 1939. Not really worth it for the Italians. Now the ZB-26 (different from the 30/Bren due to caliber) already used 8mm Mauser and would be cheap and easy to make for the Italians and could source ammo from the Germans if needed. Plus it was designed initially with a belt feed mechanism, so could be designed with such a system and used as a MMG and replace the wide variety of crap the Italians had. I don't see why it couldn't also be used as an HMG if needed, provided the proper barrel/tripod. The British tried to do that post-WW2 with the Bren, but screwed up the feed system with a Rube Goldberg contraption; I mean if the Belgians realized that the MG-42 feed system was the way to go for the FN MAG, which didn't the Brits???
Regardless, in a lot of ways the ZB-26 was the 1930s/40s PK-series of machine guns and could have been a universal MG for the Italians and anyone else interested.