I understand that before the Marian reforms each citizen soldier was expected to provide his own arms and armour. However, after Rome addopted a full time, professional armed force how did it go about manufacturing the masses of equipment needed?
Who made this equipment and who paid them? Was prodction of military equipment handled by the state, or contracted out to private blacksmiths, ect? How was standardisation and quality control handled?
Thanks in advance.
It isn't really well understood, to be honest. In Late Antiquity, so-called fabricawere established that provided something like mass production of arms and equipment, but it isn't certain whether that was an earlier development or part of Diocletian's program of increasing state power. It is important to note that at no point did the Roman state need to supply 500,000 sets of arms, as the army was in a process of constant rotation, and so there is no real reason to doubt that individual army units could not be supplied locally. Also worth noting that equipment expenditures were docked from a legionary's first years pay.
I have read a more up to date discussion of this, but for the moment I can recall supply being mentioned in Kevin Greene's Archaeology and the Roman Economy and other details in Goldsworthy's Roman Army.
Marius asked that the state provided the weapons. An expenditure I'm sure they were willing to spend given the fact that tens of thousands of Cimbri and Teutons were at their gates and ready to destroy the Republic. I personally love Marius in Roman history, a very interesting character.
Sources: Quick Info on Marian Reforms