Before you file anything
try some different ammo. Try a bunch of different loads. You may just find one that hits close to point of aim for your gun.
I don't like to file sights, it is a permanent solution to what is usually a temporary problem. try a different brand of ammo. A different bullet weight, a different velocity. Somewhere out there is a combination that will cure your problem.
Or, it also could be you,....low and left could be a problem with your grip and trigger squeeze, not your gun and ammo. Have someone else shoot your gun and ammo, and see how they do. if they don't go low and left, the gun doesn't need work, you do.