In Forever in a Day, Teal'c shoots Sha're (still possessed by the Goa'uld Amaunet) with his staff weapon. He was forced to shoot to save Daniel Jackson from the Kara kesh, Amaunet was using on him.
However, it is well known that a staff wound can be non-lethal, if not being shot directly at the chest or stomach. For instance, it would have been sufficient to shoot her hand, thereby destroying the Kara kesh. Clearly Teal'c is aware of what his staff weapon can do.
Is there an in-universe explanation for that?