Lock Inlet, piece by piece method

[Acer Saccharum]

This is a tutorial on inletting a lock, one piece at a time. Some folks inlet the lock as one piece. I go piece by piece.

This bare plate allows you to get the plate lined up on the touchhole very accurately. Inlet your plate right into contact with the barrel. Trace thru the holes for the screws


Align the sear and bridle on the holes, and trace their outline with a pencil, then drill out for the tumbler.


Drill out any other screwheads(measure how deep, first). Inlet the bridle(which is now screwed onto the plate). Then assemble the tumbler and bridle in the plate, inlet that. Then put the sear in plate, inlet that.


Install sear spring, inlet that. Mark out for mainspring, rough drill out material with a brad point drill, drilling side-by-side holes.


Inlet Main, for all positions. Observe all the little spots that touch and hinder function. You need to be able to raise and lower the tumbler with the hammer, so you need to be able to push on the sear with a screwdriver from underneath. I use inlet black on a toothbrush to put a slight film of black on the parts. Cut relief everywhere you see black. But not the plate inlet or bolster...that's already done, and you want those to remain snug.


Please consider that the inlet doesn't have to be so darn tidy around the parts. Hardly ever was done that way in American work, pretty common in high grade English work.


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[Bill-52]

Tom,

Thanks for the lock inlet tutorial; very helpful.  One question: I noticed the triggerguard is already in place and pinned.  I assume the trigger and plate have not yet been inlet?

I've always inlet the the trigger & plate and then the triggerguard.  Probably a reflection of my limited experience and lack of complete confidence in my measurements.

Bill

[Acer Saccharum]

Bill, really good question.

For inletting the lock, it would have been helpful to have the a trigger slot cut. When you get to the place in the inletting sequence where you want to lower the cock, you can't do it if there is no slot to push on the sear with. So, yes, it is handy to have the trigger slot cut during the inlet of the lock. In proper sequence, AFTER the lock is fully inlet, then I trim the bottom profile of the stock, then inlet trigger and plate, then the guard.

If I were using a Double set, from Davis, say, I'd have bent it to the curvature I needed, and yes, inlet it, BEFORE the guard installation, but AFTER the lock is fully inlet. The triggers need to be positioned fore and aft properly so that the front trigger can be used without having to set the rear trigger, for example, when the gun is at full cock, and you don't want to take the shot, you wish to lower the hammer by hand.

The sets also need to be positioned low enough so that the lock will go into half and full cock with the set triggers set or unset.

[Acer Saccharum]

When inletting the plate, you want to get the bolster right up tight to the barrel. You can do this by eye pretty well, but how do you know it's a really good fit?


When I start going for the final fit, I slip a piece of heavy kraft paper between bolster and barrel. The bolster has a smidge of inlet black or soot on it. Tap the plate down, then pull out the paper. AH! this is printing a little heavier at the toe. I am going to inlet the tail a bit more.


As I get it close, I switch to a thinner paper. Here the print is pretty good. Fair contact fore and aft on the bolster. I checked the lockplate to top barrel flat with a square, and it looks nice and square.  So I'm going to file the bolster at this point in the process, and be done with it. No powder or burnt residue can trickle between lock and barrel, internals will stay nice and clean, free of rust.



Food for thought:

If you want more or less stock width at the tail of the lock, there are some things you can play with. For less thickness thru that area, you can file the barrel flat to be parallel with the bore. That brings the lock parallel, and brings the tail of the lock in toward the wrist.

For more flare thru the rist area, you can file the lock bolster at the toe end of the lock, which will kick the lock's tail OUT, increasing the flare thru the wrist.