GPR lock disassembly

[keving]

I am going to brown my GPR flintlock because the fake color cased hardening on the lock is not well covered over the entire lock. I left the hardening color on my percussion lock when I browned the metal on my GPR percussion rifle and it is a nice contrast to the rest of the browned parts.

I have never taken a lock apart and would like to know when I pull the hammer screw parts wont just start falling away will they? It looks like the plate that the hammer screw is threaded to is also attached to the lock plate. Im just thinking there might be small parts behind this plate that I can not see.

While I have the lock somewhat dissasembled is there anything I can do to smooth it out? It feels kind of gritty when I cock the hammer back. I think it is in the tumbler where I feel the grit. How would one go about polishing a small part like this? Thanks.

 

[Darkhorse]

First of all your GPR parts list has an exploded drawing of the lock showing all internal parts.

The part your hammer screw goes into is not a plate at all but in fact your tumbler. Your lockplate has a reamed hole in it that the boss of the tumbler goes through.
This next part is all from memory so bear with me; Turn your lock over. The little plate covering all the innards thats held on by two screws is the bridle. This plate must come off to remove the rest of the parts. Be careful you don't lose the fly, it is a little brass looking part that goes into a hole in the tumbler and moves back and forth. You need this part to use set triggers.
Before I remove the tumbler I would remove the mainspring. Since this is a coil spring an old fashioned lock spring vise won't work. This is about the only place I'll use vice grips. Wrap some tape around the end of the jaws so they won't mark up the parts. Now open them all the way up and just catch the edge of the pin and the boss the pin slides in. Gently squeeze enough to compress the spring and work the plunger out of the hole in your tumbler. Be careful here as this spring can go "Boing".
Now remove the screw that holds your sear bar in place, carefully because there is also a coil spring with a plunger inside this mechanism. Don't loose this spring either.
With the bridle off and all screws and springs removed, and the fly removed and stored. (it will fall out when the bridle is removed) Try to work your hammer loose (after removing the screw) if it won't come don't try to pry it with a screwdriver. Place your plate on blocks with the tumbler free between them and with a punch with a tapered end, gently tap the tumbler down out of the hammer. (the tapered pin goes in your threaded hole in the tumbler so it won't bugger up the threads)Feel the square sides of the tumbler that goes into your hammer. You will probably find a burr or two, stone these off and next time the hammer should slide freely on and off.
Completely clean all grit and fouling from all parts. Now check the lock plate for rough spots. If you find any remove them with a fine stone. Then find whatever scored your plate and stone that also.
Friction is an enemy. You are trying to remove friction.
Put it back together and oil it and see if it works any smoother.

If you are having a hard time figuring out how to dissasemble a lock then you don't need to be stoning any notches. So leave them alone.
Here is where you need skill as you can quickly create a dangerous situation.