Author Topic: Lock help (Read 4599 times)

Rawhide Rick · « **Reply #25 on:** December 10, 2021, 10:59:47 PM »

Not sure how to go about getting a photo of the trigger engagement, unless it's just a pic of tab as it comes into the hole in the stock where the sear tab goes in. I'll have to reinstall everything tonight to get a better feel for the trigger again. I don't remember any slop once the cock is lock all the way back. I don't know about trigger movement with the cock all the way down.

The lock appears to be all brass, I don't think it's brass plated. The builders intials are stamped on the outside of the lock and my buddy believed it to be hand built, so I'm told.

Rawhide Rick · « **Reply #26 on:** December 11, 2021, 11:29:24 PM »

More pics,

Lock appears all brass to me, even the internal threads.
.45 inch trigger travel when cock is at rest. From full cock to sear releasing the tumbler, there is over .50 inch trigger travel. Very little play in the trigger at full cock. Sear seems to engage the top of the trigger tab about 2/3 of the way back from the front edge. Hope this all makes sense.

D. Taylor Sapergia · « **Reply #27 on:** December 12, 2021, 09:00:18 PM »

I see the trigger is pinned nice and high, but only about 1/4" or so from the sear arm. There's where a lot of the trigger creep is coming from, combined with the too deep full cock notch. I'd say your only recourse to take creep away is to fill the notch as several posters have suggested. Even if you only take away some of the creep, it will be a noticeable improvement and may satisfy the owner. If you remove most or all of the creep, the sear engagement on the full cock notch will be so light that trigger pull will be light and crisp, but will endanger the sear crashing into the half cock notch on the tumbler's way to rest upon firing. That will sooner or later ruin the sear and/or the half cock notch. Your best chance for a light trigger, no creep, and light pull, is to cut the tumbler for a detent or fly. That involves the use of either a mill with a fine cutter, or die sinker chisels, a light hammer, and quite a few hours of careful precise work.

Bob Roller · « **Reply #28 on:** December 13, 2021, 01:37:13 AM »

One thing I noticed was the frizzen is unbridled and appears to be supported by a single screw that is way to small.
IF this lock is brought to the point of being usable I don't look for a long life for it.
Bob Roller

Rawhide Rick · « **Reply #29 on:** December 13, 2021, 03:47:05 AM »

My nomenclature might be off but the top pic in the last series posted has a support plate that holds the tumbler and sear, is that a bridle/bridal? I removed that plate for a better view when I took the first pics.

I’m familiar with a fly, the tiny little pivoting thing. I lost one off a lock one time during disassembly and cleaning. I’m not sure I could make and fit one without messing it up. It’s purpose is to jump past the half cock notch I assume.

I do have aluminum braze, I could build up the full cock notch with that, Then reshape it. It has a lower working temp than brass brazing, so less risk of temper damage to the tumbler. But, it sounds like you guys are leaning toward leaving it alone. If it were mine, I think I’d want it improved somehow. It would make an impressive turkey killing machine, but not with that trigger.

He wants me to recommend an approach/fix and then have at it. I suppose the lock could be fixed by someone who specializes in that, if it doesn’t respond well to my attempt.

mikeyfirelock · « **Reply #30 on:** December 13, 2021, 04:11:49 AM »

I may be way off base, but it looks to me like the angle at which the sear and full cock notch engage is a bit extreme and is producing a mechanical disadvantage which increases the effort to disengage. I’ve had to stone the sear nose and the full cock notch on a couple locks to reduce the effort required to release which was excessive. If you try this…….go slowly and check frequently. You need the proper stones for this also.
Mickeyfirelock ( shade tree certified)

Rawhide Rick · « **Reply #31 on:** December 14, 2021, 08:42:29 PM »

I be decided to try building up the full cock notch with aluminum braze. This stuff works at around 650°, can somebody chime in re: that temp range and the temper of the tumbler.

Since the sear will only be resting up against the braze and not wearing on it, I'm hoping it will work.

D. Taylor Sapergia · « **Reply #32 on:** December 17, 2021, 03:56:51 AM »

It is my opinion that 650 deg. will ruin the temper of the tumbler and cause wear on contact points from then on. If you intend to fill in the notch, I'd use brass and JB Weld so that it isn't permanent.
Here's a radical approach and one for the really adventurous and confident: Anneal the tumbler by soaking in a charcoal fire at red heat, allowing it to cool as the fire dies. Drill a hole through the tumbler from above the notch and thread 2 x 56. Install a screw so you can adjust the trigger engagement in the notch from above. Re-harden and temper the tumbler. Bob's your uncle.

Rawhide Rick · « **Reply #33 on:** December 17, 2021, 05:46:55 AM »

You had me hooked until the reharden and temper part. Back to the JB weld.

Dphariss · « **Reply #34 on:** December 17, 2021, 05:13:58 PM »

Quote from: Rawhide Rick on December 17, 2021, 05:46:55 AM

You had me hooked until the reharden and temper part. Back to the JB weld.

Like Taylor said…

Heat the tumbler to grey or higher to anneal drill and tap. Get some Cherry Red hardening compound. Wrap ( if it does not have a handy hole) the tumbler in some soft steel wire for a handle, heat tumbler to nice cherry red, dip it in cherry red its gonna make nasty smoke. Reheat to a nice high red close to orange. The quench in at least a quart of warmed 120 degree at least, light weight oil like ATF and Marvels mystery oil 50-50. Then clean removing any left over compound and get ALL the oil off. Check for harness with a file if it skids off then POLISH it with 400 or 600 grit paper.making SURE its completely degreased, especially the tumbler screw hole, preheat the kitchen oven to 425 or maybe even 450. Put the part in the oven on a sheet of aluminum foil and leave it for an hour. It should have a light/medium tan color if not increase the temp by 15-20 and give it another soak time. When the color is light straw color shut off the heat and open the oven let it cool. Dark straw/brown/blue is a little too soft.
Should be good to go. This is not rocket science. But you might need a MAP gas’s torch or two propane torches. I heat a block of steel in the forge to get the oil hot. COLD OIL IS NOT GOING TO WORK RIGHT. The Casehardening compound is to prevent surface de-carb. AS Mr Brooks stated this lock was not intended to have a good trigger pull.
If you are going to let people give to stuff to fix you need to learn how to fix them. This site is a pretty good class room and there is good advice here. Some states have gunmakers guilds that are also a good place to find advice. But I am only familiar with Montana and Washington.

Rawhide Rick · « **Reply #35 on:** December 17, 2021, 08:50:10 PM »

I appreciate the input. Part of my hesitation nas to do with limited available time, some is lack of experience. Under the right circumstances I would probably tackle the heating issue. Especially if I owned the gun.

Since it's not mine, I'm hesitant. In my defense, I told him I would look at it and see if it's something I could do. I'm smart enough not to make promises.

I do have some Cherry Red, if that's the stuff that Brownells sells. Didn't have much luck with it on a TC frizzen. Old timer told me to put it in a tinncam with leather scraps, toss it in the hot coals of a fire and let it sit for about 3 hours. Take it out and drop the whole thing in water. That worked alot better.

In the end, my only way to judge temp would be by eye. Back to the owner for a decision.

Rawhide Rick · « **Reply #36 on:** January 18, 2022, 05:04:16 AM »

Update.

Finally got time to take a crack at this. A thin brass shim dramatically improved the situation, but…..
If you stroke the trigger in a smooth pull, like you would with a rifle, it catches on the half cock notch. I’m puzzled at this. I did not modify the outer diameter or shape of the tumbler at all. Simply made the full cock notch shallower. I went with the shim and epoxy as it’s easy to undo.

Any thoughts on why it’s catching at half cock?

mikeyfirelock · « **Reply #37 on:** January 19, 2022, 03:36:28 PM »

I would suspect that the extra effort it previously took to separate the sear from the notch was enough to pull the sear away before it could catch ?

rich pierce · « **Reply #38 on:** January 19, 2022, 04:13:58 PM »

Quote from: mikeyfirelock on January 19, 2022, 03:36:28 PM

I would suspect that the extra effort it previously took to separate the sear from the notch was enough to pull the sear away before it could catch ?

Plus 1. No fly and a light pull will do this. They don’t warn ya about that. But muskets are not meant to have light trigger pulls. And you can quickly break your sear nose getting it caught a few times.
A rarer problem is that the trigger cannot pivot far enough because the blade inlet is not deep enough.

Rawhide Rick · « **Reply #39 on:** January 19, 2022, 04:17:28 PM »

Looks like I'm headed toward removing the half cock notch. I hate to see my friend sell the gun because he can't get past the trigger pull.

heinz · « **Reply #40 on:** January 19, 2022, 04:27:55 PM »

Do not remove the half cock notch. That is a dangerous modification because you want the half-cock to catch if the hammer slips on cocking

You can try slowly shortening and rounding the nose of the half cock notch in the tumbler. This you can do with whetstones. That gives you the slowly part.

Rawhide Rick · « **Reply #41 on:** January 19, 2022, 04:44:46 PM »

It is a dog lock, and has the best mechanism for a half cock.

But I can go at it with the stones.

I can shoot it just fine, as I don't mind punching the trigger a little bit. Like everyone is saying, it's not a target rifle. But it's not my gun.

huntinguy · « **Reply #42 on:** February 06, 2022, 10:09:33 AM »

Okay, these guys on this forum have forgotten more than I will ever know. But, I did learn a lesson on my first venture into building.
My first build was a cva kit. That lock had a a screw in the tumbler to adjust the sear engagement. I adjusted it to what was like a modern rifle trigger pull. It took less than 20 cycles of the lock to break off the half cock notch off. The sear would try to engage the half cock notch on every cycle of the lock.
The replacement lock didn't have the adjustment. I was tempted to file the leading edge of the half cock notch so it would pick up the sear and push it away from the sear as it passed by. It didn't take long for me to decide that was a bad plan as it would weaken the half cock notch. It did not take long to break off the tip of the sear using the new lock.
Someone above, mentioned to just slap the trigger. I shot my cva that way until I wore the gun out.

Rawhide Rick · « **Reply #43 on:** February 06, 2022, 04:53:49 PM »

I should have updated the progress but the lock is done. As suggested by one of the members here, brass shim stock epoxied to the full cock notch worked, and very minor filing of the half cock notch solved the catching problem. I took a couple passes at a time with the file, re assembled and pulled the trigger. Only took 2 of the cycles to solve the problem. The owner is now happy with the trigger pull

And I suppose it's a coincidence that you posted but my current project for another friend is fitting a flintlock to percussion cva mountain pistol. Both the percussion lock and the flint, have the set screw you refer to. And both have a fly as well.

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Author Topic: Lock help (Read 4599 times)