I have a post war P38 that has a cracked slide. I bought a new slide but can not get the old one to slide off the frame. I removed the mag, decocked hammer (after check for empty), pull the slide back, rotated the lever on front left. the slide moved forward about on inch and stopped. I have wiggled, cussed, yelled and begged and it will not slide off as the videos show. What have I missed or what could be wrong inside. Thankd
