I have a Charles Daly CS model that doesn't lock open everytime on the last round. After putting about 200 rounds throught it I have noticed that the cut out in the slide is being battered somewhat. What I would like to know is should I work on the slide or on the slide locking lever. This is my first 1911 and I'm not that familiar with all the names for the various parts yet but I think that you get the idea of the parts I'm talking about. Thanks to all for any and all suggestions.