I am getting my PAL shortly and my father has an 87a that I plan on using. He is getting on in years and hasn't used it in years and is a little foggy on how it works. Do any of you know how the lock on the bolt works? There is a button instead of a lever and I can be pushed in to lock it. Is this for single fire, and having it pulled out allows for semi auto? I'm very anxious to try it out having read that it is a good plinking gun. It also has scope with it. Will I have to remove the peep sight to mount the scope?