9MM ammo isn’t built for lightweight revolvers. The recoil can dislodge the bullet from the case. The following is an analysis of how much bullet creep you get for various types of 9MM ammo in a Ruger LCR 9MM.
By the way, I’ve seen this referred to both as bullet creep and bullet crimp jump. If one term is more correct than the other, please do let me know in the comments section below.