How to tune a Lock

[ebiggs1]

Unfortunately the “Resources” or “How To” articles are not updated on any regular basis. Even if they contain erroneous information or technics that are now know to not be true. :shocked2: Even if they don't, there are many opinions on what is the correct way to tune a lock or even shoot a flintlock. :hmm:
My advise is as Roundball and others have said, send it to the people that are know for their quality work, like Jim Chambers. :thumbsup:
If it isn't one of his locks and is a coil spring model I suggest you leave it alone. It's pretty easy to make a bad lock a horrible lock. :grin:

 

[paulvallandigham]

AB: I agree that lock plates need to be hard to stand the wear, and that case hardening is often the only answer. However, I consider this "advanced Tuning" which the typical shooter probably can't do himself, due to lack of equipment, training and knowledge. Welding up holes, and re-drilling them is another thing most shooters are not equipped to do. These problems relate to lock design, which falls into the category of "Advanced Tuning", too. Making replacement parts is also "Advanced Tuning", by my way of thinking.

What I was attempting to describe is how to go about doing simple tuning with hand tools, that most anyone can do, which turns mediocre locks into good performers. I learned these techniques working with a horribly made import lock on a percussion gun, and later shared information with a friend who tuned flintlocks, and did all those "Advanced Tuning" things I have mentioned. There are only a couple of "tuning" issues with percussion locks you don't find on Flintlocks.

There are all kinds of problem locks out there, still being produced. Thankfully, most current American manufacturers have either corrected defects in their designs, or make well-designed locks already. And they are already using better steels so that the wearing problems with soft iron or steel is not a problem with their locks. :grin: :bow: :v :hatsoff:

 

[Stumpkiller]

I'm new to flintlocks and I don't know much about tuning a lock, however I am a machinist and I know a little bit about the working of metal parts. I immediately noticed a few problems with some new locks. Most of the problems that I have noticed were with the tumbler. Some are too loose in the lock plate and the cock is to loose on the hammer (or cock). This drives me nuts. I can not stand sloppy fitting parts. I have been shimming the hammer fit on the tumbler but I don't like to use shim to fix something that should have been corrected at the time of manufacturing.

You want to be careful in that tightening some screws in a new flint lock will cause more problems; or stop it from working entirely. The bridal and sear screw aparantly have some take-up designed it for wear as even high quality locks exhibit this. You tighten the sear screw and then back off 1/4 turn. Just enough applies to both tightening and lubrication. Too much is worse. If you are careful (and have a spring vice) some gentle work with fine ceramic stones can slick up a lock nicely. But I think it was Claude said above knowning where to polish and when to stop is very important.

Here's a diagram and helpful hints and tips.
http://www.lr-rpl.com/index.php?op...:parts-diagram&catid=41:information&Itemid=68

 

[ApprenticeBuilder]

Paul,

Again you have pointed out the obvious in the discussion, the devils in the details. I often times forget that just because someone asked a question, they sometimes don't really want the answer, more just trying to spark conversation, and there are many willing to step up to that plate.

The porblem with that is that the same generic details get repeated so often that they are accepted as fact and then assumed that there is no need for further information, or that the rest of the information is somehow incorrect, or unnecessary.

In all honesty the typical shooter has no business inside the lock anyway, they are likely to do more damage than good.

The basic response to polish out the scratches/gouges in the plate will achieve nothing unless an individual is ready to grind/polish the foot of the spring. Even then it may be that the tumbler hole is not drilled square, so working on the spring is useless.

If the steels were sufficiently hard there would be no need to polish out the gouges, there wont be any. The tumbler pivots vastly differently when it is loaded vrs unloaded. Here is a simple little test, take a lock and try to twist (with hand pressure) on the cock and notice the amount of movement, then remove the mainspring and sear spring and do the same test. Notice the amount of play.

Without a hard plate all of that fine tuning will go to waste, as the lock plate wears things change and other problems begin to surface.

Another thing I spose that needs to be considered, not many will shoot 200 rounds a year, most do well to squeeze off 50 a year. It changes the useable lifespan of an as shipped lock from 6 years or so to about 25.

Thats a lifetime of shooting for many.

Thanks Again for your thoughts, I value your input.

 

[rich pierce]

Originals with case-hardened lockplates are often loose as a long-neck goose, the tumbler just wallering around in the hole. Case-hardening helps a lock stay tight but there is no substitute for avoiding corrosion.

 

[ApprenticeBuilder]

Originals with case-hardened lockplates are often loose as a long-neck goose, the tumbler just wallering around in the hole. Case-hardening helps a lock stay tight but there is no substitute for avoiding corrosion.

Spose if I was 100 to 200+ years old I'd be loose and rattle around a bit my own self eh.
:grin:

 

[jerrywh]

There is another reason for this looseness in case hardened locks. Case hardening will shrink the metal some. The tumbler hole will actually be expanded a small amount or the tumbler shaft may shrink some when case hardened. This is almost always a factor but further wear is eliminated and friction is greatly reduced by case hardening. Case hardening will speed a lock up to some extent because of the reduction in friction. I can't say how much percentage wise but it is noticeable. I would estimate about 10% to 20%.

 

[Rokon]

How do you case harden a lock plate without warping it?

 

[M. De Land]

When I case harden/color an action , trigger guards and breech blocks, I generally block them with reinforcing plates with holes drilled in them. Hammers, triggers and screws are not generally blocked up.
What is actually happening is warpage not really shrinkage and it happens every time to some extent.
That is the reason single action cased steel required both soft and hard fitters at the factory.
The parts were filed to mate and then case hardened. The parts had to be re-mated after the casing because of minor distortion when quenching and this was done with stones and abrasive lapping.
Even blocked parts will warp to some extent but nothing like if they are not. Mike D.

 

[juancho]

I had my first build in Dec '11.Not exactly knowing how to "tune" a lock, I used my 30+ years as a toolmaker as my only guide.
I had every component case harden, even the screws.
I have no gun tuned to compare it to, but I'm quite satisfied with the results.
A few weeks ago, I was told at the range that my lock was astonishingly fast, by a guy that has seen quite a lot of guns.I said , yea , is Ok.
No,He relpied, is like a percusion lock.
I gess I got first time luky on this one. :grin:
What I don't know well , is the efect of the flint on a good vs a not so good lock.
Can a so so flint make a good lock bad, or a good flint make better a not so good lock?
I gess the shape, thickness and length of the flint has some kind of efect on the point of contact and angle with the frizzen.

 

[greggholmes]

here is a starter

Link

 

[don hepler]

Great link, and some really good information. I guess my machining background has served me well, because I figured out a lot on my own.

Interestingly, two guys showed up at the range with modern bp rifles, and had never seen a flintlock fired. The first words that came out of their mouth, " I can't believe how fast that gun went off.""We were expecting a delay."

Then, I let each one fire a round. The smiles, were ear-to-ear. The big Siler lock, seemed to be showing-off on it's own. Standing behind the rifle, as each guy fired, I could not detect any noticeable delay. A well tuned Siler, is a joy to own.

Oh, and the most interesting part---the flintlock was shooting groups, about 2" at 50 Yards, as compared to the modern rifles, which were about diner plate size. Even, their shots with the flintlock, was much better, than what they were shooting. Had to be humiliating.

 

[Vaino]

Most of the Chambers' flintlocks that are used in my LRs need only deburring and some addt'l relief for contact surfaces.

When a new lock is rec'd, the timing is first looked at...tumbler doesn't extend beyond the lockplate, any rub or score marks and warped lockplates.

On the just finished Lancaster using a Dale Johnson, the trigger pull was hard and creepy and I knew my trigger pin location was correct for a lighter trigger pull, so some work had to be done w/ the sear/tumber engagement. In effect, the sear movement w/ the tumbler "ledge" {notch} was fighting the mainspring. Some minutes of judicious stoning of the tumbler "ledge" yielded a 3# pull w/ a minimum of creep.

Some flintlocks require a lot of work for proper function and even Chambers' locks can be gone over and improved. Any lock "tuning" requires some know how, otherwise new parts may have to be ordered.....Fred

 

[kaintuck]

Oh, and the most interesting part---the flintlock was shooting groups, about 2" at 50 Yards, as compared to the modern rifles, which were about diner plate size. Even, their shots with the flintlock, was much better, than what they were shooting. Had to be humiliating.[/quote]

:shocked2:
the 6.5x55 sweds will shoot sub inch groups with everyone I have ever had!...same with 7.5swiss carbines......modern guns seem to be loosing!
as for the flinters groups....seen ALOT that with tinkering, will raggy hole at 50yds......

the british at New Orleans couldn't believe the long range of them flinters either....untill they had to tuke tail and run home!!!!!!!

 

[Billnpatti]

Fully tuning a lock requires the work of a smith that specializes in tuning locks. There are a couple of things that you can do to slick it up a bit but you have to be darned careful when doing it and you need a fine stone with sharp edges on it so you can get up close and tight when honing the full cock notch and trigger. First to do this, you need to know how to disassemble your lock and have the proper tools. The main things you need in the way of tools is a spring clamp (or spring cramp as some references call it), a set of fine sharp edges stones and a set of gun screwdrivers. Don't use regular screwdrivers because the way the blades on regular screwdrivers are made, they will slip out of the screw slot and booger up your screws. With those tools, and the necessary knowledge you can properly disassemble your lock and use your stone to carefully polish the full cock notch and trigger where they engage. You must be very careful to just polish these surfaces and not change the angle or round off the edges. If you happen to do this, your lock will not stay fully cocked since the trigger will want to slip out of the boogered full cock notch. Care and a good magnifying glass will help you to avoid these errors. Or you can just send it to a good smith that specializes in flintlock tuning.

Oh, and don't try to remove flat springs with something like Vise Grips to channel lock pliers because they can very easily break your springs. If you don't have a spring clamp or know someone who will lend you theirs, do not attempt to remove any of the flat springs (main spring or frizzen spring) from your lock. Cause you sure can break them.

Keeping your lock clean and lightly oiled on all of the engaging surfaces will make it work much more smoothly. Some folks do not clean their locks after each time they shoot their gun but I chose to clean and oil mine every time. I use either automobile brake cleaner or carburetor cleaner in spray cans. They both work equally well. Remove the lock and take it outside on the driveway and spray it out with the cleaner and let it dry. It dries very quickly. Then I apply a drop of a good gun oil such as Remoil or 3 in 1 to the surfaces where there is movement of the parts. I don't use Barricade because it tends to thicken up. It is great on the rest of the gun and my gun oil of choice for the rest of my gun but just not in the lock. Wipe off any excess (excess oil just grabs dirt and fouling when you shoot) and return your lock to your rifle. Just snug your lock bolt(s), don't over tighten them by put the King Kong on them. You can over tighten them and cause problems. Just nice and snug is the proper way to do it.

 

[Grandpa Ron]

While hanging around the gunsmiths’ hall at the Fall Nationals in Friendship, I listened to two of the gunsmiths discussing just this issue.

Both agreed that a good lock just has the proper “feel” as it was being cocked or fired and that the correct geometry was important. Both also commented on the number of people who spend a lot of time trying to improve on an already good lock design. :hmm:

I have watched the high speed videos of the various flint locks that one can find on the web and it would seem that the speed of the lock is over shadowed by the ignition time of the primer powder and the transfer time of the heat pulse to the main charge.

I would venture to say that for the average shooter, the improved lock speed is lost in the normal variations of the priming powder and the main charge ignition times.

This is not to say that lock tuning is a bunch of hokum, it is more like picking up a fine musical instrument. Above a certain level of quality, “better” is more feel and nuance than actual measured response.

 

[don hepler]

I wasn't talking about a modern centerfire rifle, they had modern muzzle loaders, shooting some kind of maxi-ball, I think the bullets were made by Remington. They were the inlines from a few years back, looked like they were rode hard and put up wet.