Ammo today is readily available from several sources. The same for brass to reload the 7.5x54. For reloading, the 7.5 can use the same .308” diameter bullet as many other rifle cartridges.
When ammo was hard to find, the 6.5x55mm Swede Mauser only requires one pass in a 7.5x54 FLSD to open up the neck and ready to be reloaded. Other brass such as the 7 or 8x57mm Mauser, 7.65 ]Belgian (Argentine) Mauser and even including the .30-06 could be converted to 7.5x54 without much fuss.
The French never had safeties on their rifles for many decades, although the Mas 1936 could be carried with bolt handle slightly raised and it can not be fired. The Mosin Nagant M91 rifle has the appearance of a safety, but it was/is seldom ever used due to the difficulty of setting it for most people.
I remember at the time I knew it was easy to make the French round from 6.5X55 but I didn’t want to use up any of my Swedish Mauser brass either.
I did not know about the .308 brass. Anyway I never got one and they are not common now.