Polishing lock internals

Help Support Muzzle Loading Forum:

HarvinTx

40 Cal
Joined
Jan 8, 2022
Messages
156
Reaction score
108
I will definitely show my ignorance with these questions.
What is meant by polishing the lock internals? How is it done? What is it supposed to accomplish?
 

Loyalist Dave

Cannon
Staff member
Moderator
Joined
Nov 22, 2011
Messages
12,689
Reaction score
7,351
Location
People's Republic of Maryland
Alright, so parts inside the lock rub against each other. The sear and the tumbler actually scrape against each other. So one way to improve lock performance, i.e. faster movement of the parts ; less wear..., is for the surfaces of the moving parts to be polished very smooth. This term may even refer to polishing the surfaces where the sear and the tumbler meet to reduce trigger pull because the friction has been reduced between the two parts.

This is often done by hand with emery paper and oil. The side of the sear, the sides of the tumbler, the inner edge of the main spring may be polished. Some folks have had the inner surface of the lock plate polished by power tool known as jeweling, but I recommend that powder tools be avoided.

BEWARE: it is possible as mentioned to polish the full cock notch and the tip of the sear where they interface, BUT those two parts must have proper angles to properly function. and the quickest way that I've seen for a lock owner to make mistakes is by polishing those two locations while not knowing or being able to maintain those angles. Also it is dangerous for folks to try to polish the large hole in the lock plate or the surface area of the tumbler that rotates within that large hole, as that too can be over polished and render a lock with minor problems into a wall-hanger-only situation.

LD
 

rich pierce

70 Cal.
Joined
Nov 27, 2004
Messages
5,659
Reaction score
2,056
Location
St. Louis, Mo
See Dave above. Good info there. This was typed while he was posting.

Reasons: 1) Reduce friction. 2) look like an original lock, not something made of unfinished bead blasted lost wax cast parts.
It’s done by judiciously using files, stones, and fine abrasive paper or cloth carefully backed. Look up lock tuning. There are do’s and don’ts. The polishing can vary from selectively polishing friction bearing surfaces to polishing everything visible. Too complicated to cover in a short answer. If not well understood and executed, more harm than good can be done.
 
Joined
Nov 25, 2019
Messages
920
Reaction score
699
As stated you need to understand why you are polishing this or that. It can get in tuning the mechanism. Many locks are slapped together from rough unfitted cast parts. The problem is that certain relationships need to be properly fitted for decent function.

I spent time yesterday on a pedersoli yeager lock. Just about everything was sub standard. The tumbler fit in the bridle and lock plate was very sloppy. The bridle was too tight to the plate, the bridle screw needed to be loose to allow the tumbler to rotate. The full cock notch was set an angle that caused the cock to move foreword when you pulled the trigger, before it released. That was overcome with a massively over powered sear spring. The sear screw was way too small and the sear nose was to short. The short sear made it so only short flints clear the frizzen at half cock. The pan did not fit the frizzen at all, there were large gaps. There was no clean up of the milling machine burs before sandblasting and case hardening. It is the worse expensive lock I have ever worked on. It can all be fixed with enough work and knowledge. That work was made more difficult by the case hardening.

Sometimes polishing alone is not the solution. A sloppy poorly made lock will not be made better with polishing alone. Did the lock fire the gun before I worked on it? Yes.. Did it do so safely and efficiently, no. After making parts and fitting others, it is safe and works better. I did cut my losses and stop there. To make it right would require many new handmade parts. The time required is not justified in this case. A better solution would be to get a new quality lock kit with a blank plate and start over. Franky, based on reputation I was shocked at how awful the lock was.
 
Last edited:

HarvinTx

40 Cal
Joined
Jan 8, 2022
Messages
156
Reaction score
108
A big thank you for all of the greaat information. I will do alot more reading on this subject before I give my lock a polish. Again, thank ya’ll.
 

HarvinTx

40 Cal
Joined
Jan 8, 2022
Messages
156
Reaction score
108
As stated you need to understand why you are polishing this or that. It can get in tuning the mechanism. Many locks are slapped together from rough unfitted cast parts. The problem is that certain relationships need to be properly fitted for decent function.

I spent time yesterday on a pedersoli yeager lock. Just about everything was sub standard. The tumbler fit in the bridle and lock plate was very sloppy. The bridle was too tight to the plate, the bridle screw needed to be loose to allow the tumbler to rotate. The full cock notch was set an angle that caused the cock to move foreword when you pulled the trigger, before it released. That was overcome with a massively over powered sear spring. The sear screw was way too small and the sear nose was to short. The short sear made it so only short flints clear the frizzen at half cock. The pan did not fit the frizzen at all, there were large gaps. There was no clean up of the milling machine burs before sandblasting and case hardening. It is the worse expensive lock I have ever worked on. It can all be fixed with enough work and knowledge. That work was made more difficult by the case hardening.

Sometimes polishing alone is not the solution. A sloppy poorly made lock will not be made better with polishing alone. Did the lock fire the gun before I worked on it? Yes.. Did it do so safely and efficiently, no. After making parts and fitting others, it is safe and works better. I did cut my losses and stop there. To make it right would require many new handmade parts. The time required is not justified in this case. A better solution would be to get a new quality lock kit with a blank plate and start over. Franky, based on reputation I was shocked at how awful the lock was.
I am shocked too. I have two Pedersoli’s that I have yet to take to the range. Armed with what you’ve posted I will be on the lookout for those issues.
 
Joined
Nov 25, 2019
Messages
920
Reaction score
699
An alternative to slip stones is diamond laps. I have them for engraving tools already. Since they are large maintaining the correct angle and not rocking the lap is easier. I see credit card size diamond sharpening plated in the hardware store. You can cut a sharp safe edge on them with a belt sander. This allows you to get down to the bottom of the sear notch.
 

Latest posts

Top