Parts wear doesn’t become much an issue unless you shoot the rifle with too much gas or hot machine gun ammo. If ether of these happen too much the hammer spring will wear fast because the carrier hits it so hard. This will create problems like hammer pinning. Also the gas tube will crack and leak unless it’s the Steyr soldiered type this happens due to using corrosive ammo, heat from heavy full auto fire, or long term erosion from blank fire. Recoil springs in the FAL will last a long time BUT will corrode and lose properties if you do not keep them greased and the recoil tube somewhat clear.

But what out a doubt the single biggest issue I has seen overseas besides broken furniture and charging handle knobs is the firing spring. They get weak from drills and dry firing and lead to slam fires.