As for ammo, I just reload the Frontier brass that's all over e-bay using the cheapo Lee dies. Workes fine. Hornady publishes the data and the bullets are 150gr .308 bullets. IMR4895 is pretty much standard for this round.
As for bores, most MAS rifles I see have great bores. Most were refurbed in the 50's and got new tubes at a time when the French no longer used corrosive ammo. Unrefurbed ones can have great bores too, but sometimes are thrashed. It's not hard to look down the bore and see for yourself. Despite being heavily used looking on the outside, mine's got a new bore and shoots like a laser beam. The sights are very good too with a receiver mounted peep.