inletting percussion locks

[Trapper]

Calling all gunsmiths: I'm building a scaled down Lancaster style rifle for my wife. She has asked me to build it with a percussion lock that could have a flinter installed at a latter time if she so desires. The stock is a blank that started from a very nice piece of Black Walnut. Now, I've built 5 flinters but what is the difference in locating the lock and drum compared to the flintlock and vent liner? Jim Chambers said to install the percussion lock first and his flinter will just drop right into the inlet of the percussion lock.I need a little help. How about a percussion lock and drum tutorial?

 

[Zonie]

Jim Chambers is correct (as usual).
If you locate the drum for the Percussion lock, the threads will be in the right place for a Flintlocks vent liner.

The stock will have to have an additional cut made for the flintlock's cock.
The reason for this is the Percussion hammer stops when it hits the nipple so there is no other stop for it.
The Flintlocks cock has a small shoulder that stops on the upper surface of the lockplate right behind the pan. The extra material on the cock for this stop must have clearance in the wood cut for it.

If you can afford to buy two locks, I would recommend doing it.
This allows you to make the necessary cut for the Flintlock cock before you stain and finish the wood and at the same time it allows you to build the Percussion gun your wife wants.

Oh, another thing: Although the locks use identical lock plates, they usually are not identical. Although the difference is small, it is best to cut the lock's mortice so that both locks will fit before you stain and finish the wood.

Have Fun!!

zonie

 

[Zonie]

Now that I've read the rest of your question, I'll give my rendition of installing a drum.
Note that there are many posts about this and some of them may not be the same as my method however, this has worked for me on the guns I've built.

Thoughts on installing a Percussion Drum:

First off, I’ll have to assume your making a pre inlet gun with the lock mortice roughed in.
If this is the case, you first have to determine where the face of the breech plug is from the rear of the barrel. Once this is found, scribe a line on the barrel flat representing this feature. (A Black felt tip permanate marker makes a good black mark to scribe these layout lines on.)
Now, determine the diameter of the threads on the drum. Lay out a vertical line that is ½ of the thread diameter in front of the breech face mark. This location will allow the installation of the drum without the threads interfering with the face of the breech plug.
Now, scribe a horizontal line in the center of the barrel flat. Where they meet marks the desired location for the drum.

Place the barrel into the stock and locate the lock into it’s mortice. Check the location of the horizontal line with the top surface of the lock plate. They should be close to being in the same plane.
Now check the verticle line which represents the center of the drum with the cutout in the lock plate. They should line up.
If they don’t line up and the mark on the barrel is forward of the center of the lock plates cutout,
the barrel will have to be moved rearward so they line up. This envolves removing wood at the breech so the barrel can slide back a little bit.
If the lines on the barrel are already too far rearward, it means you will have to install the drum threads further forward. This is OK, as it just gives a little more room between the breech plug face and the outside of the drum threads.

Sooner or later, you will have finally determined where the drum threads need to be.
When this point is reached, use a very sharp nail or punch and strike a small dimple at the intersection of the lines that represent the center of the drum.
Take a small drill bit (1/16 dia) and carefully drill the dimple out. Go maybe 1/32 inch deep with this. Then use a larger drill like a 1/8 inch diameter and increase the size of the drilled hole. Drill about 1/16 inch deep.

Now using the correct size tap drill, drill thru the barrel wall. (don't get carried away and drill thru both walls. :grin: )

After drilling thru the wall, proceed to tap the drilled hole with the correct size threads.
Note: You must lubricate the tap with a good thread cutting oil. Plain oil will not work very well (if at all). Most hardware stores sell sulphated oil that is made for threading steel parts. Use it. You won't be sorry and the small price is worth it.
Also, in case you haven't tapped a hole before, have your wife help you by eyeballing the tap as your starting it. It must be perpendicular to the barrel and two sets of eyes looking at the tap from different directions works much better than one set of eyes.
When you start the tap, push down gently and rotate it until you feel it bite into the metal.
Rotate it about one turn more, then stop, unscrew it about 1/2 turn, then screw it back in until it starts to get tight, add a little oil and make about 1/2 to 3/4 turn into the hole. Then back up 1/2 turn. Repeat this until the tap has fully threaded the hole.

You will probably have to enlarge the cutout for the drum in the lock plate to get a nice snug fit between the two but don't do this until the lock is fully inletted into the stock.

That ought to be enough information to get you going for now.

zonie

 

[Birddog6]

:thumbsup: Nice tutorial Zonie !

The only thing I would do differently is I would buy the Flintlock & inlet the lock completely & get the barrel/pan fit perfect, Get the lock plate drilled & tapped, & make sure a vent liner is the correct length & fits. Then take it & the lock off & install the Percussion lock & drum.

This way it is all ready to go if you want to change it to flintlock later, no cutting, filing, changing of wood or metal, take the drum off & you can have the pre-fitted vent liner in & the flintlock installed in 5 minutes .....

:thumbsup:

 

[Trapper]

Thanks Zonie, Nice tutorial. The stock is being carved from a Black Walnut blank, so is this going to make a difference in lock location? Normally when I put in a vent liner in, the lock is inletted first and I use the pan for the layout lines to locate the touchole in the center of the pan. I just wondering if I could use this same method to locate the drum, seeing as I'm inletting the lock in a blank. All my touchholes have landed at the breech plug face and I have to carefully file a cone around the breechplug for the threads of the liner. If I use my method I think that this will happen to the drum. I have always followed Peter Alexander's book and have had great sucess. I'm just a little nervous about installing a percussion lock and drum. I'm probally just being over paranoid of screwing up my wifes gun.

 

[Frank/Pa]

I have always found it is easier to locate the lock if I install the drum first.

 

[dlocke]

Alexander does tend to make installing a drum, nipple, and percussion lock seem like brain surgery. I think Zonie has the technique nailed.
DJL

 

[Zonie]

Trapper: No, it shouldn't make any difference.
Putting the lock in first and adjusting the position of the vent liner will work, but the chanches of ending up with a vent liner/drum threads which interfere with the face of the breech plug is greater if you let the lock dictate the liners location without reguard to the breech plug.
I suppose either way will work as long as the relationship between the barrel and the lock end up correctly.

When making a gun without the lock mortice existing I have always used the theory that the barrels breech plug face and the center of the barrel flat dictate where the lock should be located.
As your stock doesn't have a pre cut lock mortice, that's the way I would do it.
That doesn't mean it's the only way to do it though.

zonie