Who Ever Heard of 'Lockplate Polishing???'

Southron

Sergeant
Joined
Dec 27, 2011
This is one of those "Rifle Building Secrets" that are often found on custom built guns. When I refer to "lock plate polishing" I am referring to polishing the INSIDE of the lock plate. Here is what I do:

(1) I dis-assemble the lock and put all the parts in one of those plastic boxes with a lid. This keeps the parts from being lost.

(2) Then I use a small piece of flat steel as my "sanding block." I simply wrap a finer grade of Emery Paper (600 Grit) around it and start polishing the inside of the lock. I generally do this while sitting in the easy chair at home watching TV. The "trick" is not to get in a hurry.

(3) Then I use progressively finer grades of Emery Paper until the inside of the lock is polished "mirror bright." I also polish the arbor hole in the lock plate for the tumbler and the body of the Sear Screw. How "bright" do I get the back of the lock plate? When I can see my face in the polished back of the lock plate, I consider it done.

(4) Then I lightly oil the lock plate and set it aside.

(5) Then I carefully polish the other lock plate parts that either rub against each other in the "firing cycle" OR rub against the back of the lock plate.

(6) I will usually grind a bit off of the Sear Spring to weaken it just a tad. The Sear Spring directly affects your "Trigger Pull." I grind down the spring about 1/4th of its across the width of the arm that contacts the Sear.

When grinding down the Sear Spring I will hold it in my bare fingers. This is so I can feel it when it starts to get hot. When it does, I dip it in water. The idea is to keep from getting the Sear Spring so hot that it destroys the "temper" of the spring.

So what does all of this accomplish?

First and foremost, when the lock is re-assembled and lubricated, the "Trigger Pull" of the lock will generally be decreased to somewhere between 3 and 6 pounds of "Pull." The "ideal pull" and the N-SSA minimum is 3 pounds.

The BIG ADVANTAGE of this approach is that I do not have to mess with the stoning the sear nose and the "full cock" notch in the tumbler. These angles have to be kept precisely the same or the lock will have a tendency to catch in the "Half Cock" notch when the shooter attempts to fire the gun. Enfield locks are especially prone to this malady from a botched "Trigger Job."

Also keep in mind that "Case Hardening" is a thin"skin" of steel with a high carbon content that provides a hard, durable surface. When stoning the sear and sear notch it is awfully easy to break through that "skin" of hardened metal to the soft metal below. If you do, then your "trigger pull" will be constantly changing as the metal in the sear nose and tumbler notch deform and eventually making the gun unsafe to use.

Just to be on the "Safe Side" when I have to do some sear stoning, I always caseharden the lock parts just as a matter of general principal.

ANOTHER ADVANTAGE of a fully polished lock is "Decreased Lock Time." That is defined as the time from when the trigger trips the sear and the hammer begins its fall to the instant the gun fires. This reduced lock time is caused by the lessened friction in the lock because of the polished surfaces of the lock parts move easily and faster. Decreased lock times definitely enhance the accuracy of the rifle.

So, all in all there is a lot to be said for Lock Polishing, especially if you want enhance the "accuracy" of your rifle.
 
A "Quick and Dirty Save":

You and your Skirmish team are within two events of winning the Musket Team Match at a Skirmish. For whatever reason, that is when the Inspector get out a Trigger Weight and decide to check everyone's "Trigger Pull" for the minimum of 3 pounds.

You are concerned your Trigger Pull is too "light" to pass inspection-what to do???

Don't Panic....

While the Inspector is distracted weighing the Trigger Pull of your team mates, quickly pull the lock from your musket. Then T-I-G-H-T-E-N down HARD your Sear Screw. [Not so hard you overstress those parts though.]

A tight sear screw can increase your Trigger Pull weight by a couple of pounds! Of course, after your musket passes inspection, you can pull your lock again and loosen your Sear Screw a tad.

This one of those "tricks" that to my knowledge has never been published before. So by reading this you are bound to an Oath of Secrecy
 
Apparently not, as there is no rule against tightening your lock screws.

I don't like shooting a musket with a trigger pull of LESS than three pounds-because that is what I am used to.

Back in the 1970's one fella was caught using a "Single Set Trigger" that was originally built for a Match 45-70 TD Springfield! Now that was Cheating!
 
I'm referring to when your team is selected for a lottery spot inspection and you said "While the Inspector is distracted weighing the Trigger Pull of your team mates, quickly pull the lock from your musket. Then T-I-G-H-T-E-N down HARD your Sear Screw." You have inferred that the individual knew ahead of time that his/her trigger pull/half cock wasn't legal so they quickly made an adjustment while awaiting their turn for inspection. If that isn't cheating, then I don't know what is! Of course, perhaps that is why the N-SSA now uses two (2) inspectors for each team inspection process! :wink:
J.
 
Heck, I use to be an Inspector!!!

In all fairness, one is assuming that one's lock is below the minimum trigger pull. Even IF it is not, tightening the sear screw is just good "insurance" and there is no rule against it.
 
Let's dissect the above statement, "...one is assuming that one's lock is below the minimum trigger pull... tightening the sear screw...and there is no rule against it."

The N-SSA's rules have been tweaked hundreds of times in the past 60 years an attempt to prevent just the very thing Southron thinks is OK to do. His scenario is: The individual went to the firing line with an arm that he thought, or knew, was below the N-SSA legal limit, which is with the lock set at full-cock the musket/carbine must be able to pick up a NRA 3 pound weight. So, there you are standing line awaiting your turn for inspection and furiously trying to make a last minute adjustment to your lock because you think the trigger pull isn't legal! Those very types of actions is why the N-SSA's set of rules now contain 217 pages!

My question to Southron then is this: When you were a N-SSA certified inspector did you condone a competitor adjusting the lock so they could pass the trigger pull inspection test while he/she was standing in line waiting for you to check it for legality?

J.
 
Never heard of lack plate polishing. I have enough trouble keepin all the handguns and rifles brass polished, along with my cars.:frantic:
 
The info Southron posted on tuning up a lock is also applicable to any muzzle loading lock, be it flint or percussion, military or sporting. It would even apply to the reproduction Spencer locks if they needed it.

J.
 
The reality is I never found anyone that was purposely "cheating," I am not saying that didn't happen but on several occasions I did run across arms that, due to "wear and tear" were slightly below the 3 pound minimum. Even with a NRA Trigger Weight, the"Trigger Pull" test is somewhat "subjective." It all depends on how the test is administered.

Placing the arm of the weight on the trigger and then g-e-n-t-l-y lifting the weight off of the ground might not "snap" a lock while simply attempting to lift the rifle and weight in a "normal" manner would "snap" the lock. Trying to lift the weight off the ground with the barrel pointed 90 Degrees upward might "snap" the lock while pointing the barrel backwards ten of fifteen degrees from the vertical might not "snap" the lock.

The reality is that a lot of rifles have passed the Trigger Pull test by tightening the Sear Screw-this has been going on in the N-SSA since (I guess) around 1950. Look at it this way-IF tightening the Sear Screw will make a rifle "legal" then there is "no harm done" IF the trigger pull dropped below 3 pounds due to "normal wear and tear." Technically the rifle has been"fixed" and is now "legal."
 
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