Well at lower levels in the earlier parts of the game(where I am so far) most of the guns you find aren't in the best condition and can only be repaired to a certain percentage. I still haven't found a firearm that can go above 75% condition, most of the one's I have right now are 50% or less. This effects accuracy alot, especially long range, don't expect to be sniping guys heads off from 500 yards with that rusty sniper rifle you pick up.