You didn't change grips on it did you. The only grips that will work on it are the ones that came on it. I bought a new one about 6 months ago and had to send it back 2 times before I sold it. The store will not sell another one and won't
even take one on trade or pawn. The one I have slung parts everywhere after 200 rounds. As far as the jamming goes, they have a certian way to load the clip or it will jam. Read the instructions carefully, this is a different breed of animal.
I don't remember how long it took, but they had the gun for several weeks each time.