I’m working on a M-41, mid-70’s manufacture, that fails to fire most of the time. I am in the middle of troubleshooting and thought I’d solicit some advice. Apparently the hammer is dropping to half cock rather than all the way when fully assembled. With the slide off, the hammer drops properly. First thing I did was get the overtravel screw out of the way so that’s not an issue. I am getting ready to swap the slide with one off a known reliable shooter. Any other advice?