some ammo is more available than other, 7,62x54R floating around like 7,62x51 nato since the days of the cold war. 8x57 is one of the easier to get cartridges I suspect, also today.
sometimes guns are only held because they are a status symbol no matter what kind of gun it was like on this well known picture from somalia with a sturmgewehr 44. the beretta subgun behind in 9mm was probably feed well with ammo than.

remember when this pic came to surface, a german Mpi 38 in the lybian war. owner dont had a magazine but still hold the gun because magazine or not you are only a real man with a gun.

some italian 6,5x52 carcano was and is probably available in the old lybian colony

but I dont know where this guy get 8x50R ammo for his old berthier carabine that must have been a left over from the algerian war.

I suspect that all this old war horses were trade all over north africa for decades by camel caravan and the people who got them with a hand full ammo never thought how to get more ammo.
I suspect also that there are some clever reloader around loading the old brass again for the market dont asking for service pressure.