During the shooting portion of the CHL class the slide on my .45 Commander decided it would not lock back after the last round was fired. The pistol was not dirty. I purchased two new Wilson mags to try, since I read where there might be a problem with the original Colt magizines. These mags are seventeen years old and are kept fully charged. I tried the new Wilson mags and the slide still will not lock back after the last round is fired. Does anyone have an idea of what to try next before I have to find a 1911 gunsmith? Remmington ammo was used at the class.