I spent close to 5 hours working on an old Russ Hamm lock and triggers last year. The old timer I did the work for had built the rifle decades ago. It needed a good going over.
I found several things out of wack and loose incorrect screw. Just enough of a mixture to keep the lock from holding at full cock.
One problem was the stock wrist was so thin you had to set the triggers prior to going to full cock. I really don't know how he shot the gun , it hadn't been fired in at least 20 years; but the front trigger plate had been filed cockeyed.
I leveled out the top of the plate, added a little more bend on the sear arm then file it nice and clean.
Everything that was filed was like who ever done the work was in a hurry. All the file work was at an angle like it was never turned around in the vise.
Naturally when you start a project like this it's file a little then check fit/function 50 times.
I got it to hold nice and hard, let off was great!
Returned the rifle , explained what I had done. I said you have to set the trigger prior to going to full cock. I'm sure it was like this prior to me working on it. Damn if he didn't call me back a day later stating it would not hold! I asked, did ya set the trigger first? Ah no, I forgot. Poor old timer he nice nuff guy?
I worked on 3 ML'res and one he claims he can't find?
It was a match to the rifle. I told him he never gave me a 54 pistol it was a 45. I even corrected him when it was handed to me for the first time.
So I started a new policy to which I'm holding 90% true on. You want you XYZ worked on by me. You have to drop it off at the LGS where it is tagged and work to be performed noted. When I go in I look XYZ and give my opinion on repairs needed prior to disassembly.
Over tightening of the lock place screws is another deal that will jam a lock up.
Most of the time I find lack of lubrication,dirt, loose bridal screws to be the problem.
As stated earlier.
Without having the lock in my hands it is hard to tell what the problem is.
Another really big issue is guys can't give a good description of their problem because they don't know. Asking questions helps, but when 50 people on facebook chime in and 45 of them are giving bad/sideways don't understand themselves kind of advice, you can only hope that person listens to you.
R,
BPB