Author Topic: Lock help (Read 4605 times)

Rawhide Rick · « **on:** December 08, 2021, 05:48:45 AM »

Brought to me by a buddy with request that I do something about the incredibly long trigger take up, before the cock trips. This appears to me to be a very deep full cock notch. Can this be remedied by a non professional (me)? It is a hand made lock plate made by the builder, dog lock, on a huge club butt Fowler. The builder was consulted by the guy that had the gun built and said it should be that way. I’ll take his word for that, since this gun and several others he has built are beautiful guns.

What kind of geometry has to be maintained? Will a shallower full cock notch then catch the half cock notch when the trigger is pulled? Is there a solution other than fine file or stone to fix the issue? It bothers my buddy to the point that he is considering selling the gun. It was built to his specs and it’s an impressive piece. I’d like to be able to do something to improve it.

rich pierce · « **Reply #1 on:** December 08, 2021, 05:56:59 AM »

Adding steel or even braze to the tumbler in the full cock notch area would reduce the depth of the notch and move the sear nose closer to the edge.

That being said, a trigger with a pivot very close to the sear arm will lead to a long trigger pull. In this case both the lock and trigger may be contributing to the long pull.

EC121 · « **Reply #2 on:** December 08, 2021, 06:27:34 AM »

Degrease the tumbler really well and solder a piece of brass sheet right above the full cock notch to shim out the sear nose. Solder-it paste will work and won't get the tumbler hot enough to hurt the temper. However, having a light, short-travel trigger without a fly can lead to other problems like breaking the half-cock notch(or sear nose) or having the sear nose catch in it.

smart dog · « **Reply #3 on:** December 08, 2021, 03:20:59 PM »

Hi,
You could lighten the pull by stoning down the full cock notch, however, it appears in your photo that the lip of the half cock notch currently may be higher than the lip of the full cock notch. By higher I mean the distance from the lip to the center of the tumbler spindle. Lightening the trigger pull may result in the sear catching in the half cock notch when the lock is fired. You may have to work on both tumbler notches to make the lock work with a lighter trigger pull with less travel.

dave

Rawhide Rick · « **Reply #4 on:** December 08, 2021, 04:27:28 PM »

The trigger is pinned directly through the stock. No trigger plate. I assume this is a feature of the gun style.

Stoning the full cock notch is the easiest approach, but I'm guessing I shouldn't be doing that to the half cock notch if it ends up in the way. Had that on a used Fowler I picked up a few years ago. Someone had worked the full cock notch so it was pretty good, but if you weren't deliberate with the trigger pull, it would catch at 1/2 cock.

I can try to solder something, but will have to locate sheet brass. Wonder if I could take an empty brass case, cut a piece out and hammer it to thickness?

deepcreekdale · « **Reply #5 on:** December 08, 2021, 04:33:52 PM »

My question is why is there a half cock notch on the tumbler on a doglock? This picture shows the proper "half cock" notch for a dog lock. I would weld up that half cock notch and file/stone it smooth. Then stone the full cock notch to the proper angles.

EC121 · « **Reply #6 on:** December 08, 2021, 05:11:09 PM »

A cartridge will work after annealing. Shim stock will work. An auto parts store might have some or buy a set of brass feeler gauges.

Bob Roller · « **Reply #7 on:** December 08, 2021, 05:58:19 PM »

Quote from: deepcreekdale on December 08, 2021, 04:33:52 PM

My question is why is there a half cock notch on the tumbler on a doglock? This picture shows the proper "half cock" notch for a dog lock. I would weld up that half cock notch and file/stone it smooth. Then stone the full cock notch to the proper angles.

Bonehead simple device.Pull the cock back and the latch falls back.Simple,Huh??
Bob Roller

Rawhide Rick · « **Reply #8 on:** December 08, 2021, 08:59:00 PM »

Never had access to a dog lock before. The lock plate looks hand made, the internals, I don't know. Maybe an appropriate size tumbler meant for another style of lock or something that was built for another custom lock and appropriated for this project.

I like the idea of closing up the half cock notch on the tumbler. Seems like the easiest solution. Especially if it's correct for the lock.

I appreciate the input.

P.W.Berkuta · « **Reply #9 on:** December 08, 2021, 08:59:50 PM »

Before I would solder anything on the tumbler I would JB weld a shim on the tumbler to see if adding this shim will improve the trigger let-off. Using solder requires heat and if you are not careful with the heat you will remove some or all of the hardness of the tumbler - my two cents $:-\$

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Rawhide Rick · « **Reply #10 on:** December 08, 2021, 10:44:59 PM »

JB Weld is a good option, at least it's not permanent.

Grinding the 1/2 cock notch would be permanent. Apparently getting rid of it has no impact on the overall function of this lock type?

Scota4570 · « **Reply #11 on:** December 09, 2021, 12:21:17 AM »

Does it work?? If the pull is smooth and long, but not too heavy, I would leave it alone.

I have been burned on a project like this and ended up making a tumbler. IF the pull is reduced by whatever method there is a good chance the sear will catch on the half notch and break parts.

I never understood why anyone would make a tumbler with the half cock notch higher than the full cock notch.

Rawhide Rick · « **Reply #12 on:** December 09, 2021, 04:32:11 AM »

It does work as is but it’s a god awful long creep before it breaks. I wouldn’t consider hunting with it.

D. Taylor Sapergia · « **Reply #13 on:** December 09, 2021, 09:09:23 PM »

When you reduce the depth of the full cock notch, as has been suggested, you will also lighten the trigger pull too. Remember that this isn;'t a target gun and doesn't have a detent in the tumbler, so you will definitely run into issues with the half cock notch.
I'd like to see a photo of the lock in half cock position: that notch looks way too big for the tip of the sear's nose, so one might be able to re-cut the half cock notch to make it more effective, and then take away the outside of the curve on the tumbler so that the sear would pass the half cock as the cock falls. So post a picture of the inside of the lock at half cock please.

Bob Roller · « **Reply #14 on:** December 09, 2021, 11:41:34 PM »

That short lower arm of the sear spring looks very strong to me but little can be done about it.
Bob Roller

Rawhide Rick · « **Reply #15 on:** December 10, 2021, 04:56:29 AM »

The sear spring is beefy.

I thought about chucking the tumbler in the lathe and shaving some off the 1/2 and full notches but I’m not sure it’s a consistent arc. Easy enough to find out.

But, if my buddy doesn’t mind eliminating the 1/2 cock from the tumbler, it’s one less thing to worry about.
Wondering if a dog lock would typically have a bridle? This one does.

Not sure how to rotate it. Sorry.

Bob Roller · « **Reply #16 on:** December 10, 2021, 03:08:17 PM »

Maybe thinning the top oe sear where that stubby spring contacts it can help a bit.
Having no bridle is no help either and I wonder about a half cock PLUS an external
latch.Are both needed?
Bob Roller

smart dog · « **Reply #17 on:** December 10, 2021, 03:24:42 PM »

Hi,
Can you weld? Another thing to try is to weld steel on top of the trigger bar. Your creep problem may not just be the lock but also the trigger position. Is the trigger under pressure from the sear when the lock is at full cock or does it rattle? Welding on top of the trigger bar may be worth trying and it is reversible if it does not solve the problem.

dave

rich pierce · « **Reply #18 on:** December 10, 2021, 04:02:50 PM »

Regarding eliminating the half-cock notch - I’d avoid this or any alteration that makes a gun-owner need “inside knowledge” on how to operate it.

Mike Brooks · « **Reply #19 on:** December 10, 2021, 05:28:22 PM »

This type of lock is 100% historically correct with both a 1/2cock notch and a dog. Seems redundant but that's the way it is. Slightly earlier dog locks had just the dog

Rawhide Rick · « **Reply #20 on:** December 10, 2021, 08:04:19 PM »

While I can stick 2 pieces of metal together, it's not pretty and I wouldn't exactly call it welding. I think delicate welding is beyond me. I would also be concerned about overheating the part.

The owner is a capable shooter and operator so I'm not too worried about modifications that would cause problems for him. He is big on historical accuracy and wanted this gun to be correct. He will have to decide if the half cock notch can go, since it seems either there or not "could be" ok, from a historical standpoint.

I'm seeking expert input here because I'm not a builder, I just have more tools than the owner and an adventurous spirit. However, I don't want to screw up or devalue a beautiful gun. He is a member here so I think I'll have him read the thread and make a decision.

Is the lathe a bad idea to keep reduction of both notches even? Assuming the arc of the tumbler is consistent.

Rawhide Rick · « **Reply #21 on:** December 10, 2021, 08:09:20 PM »

Would a pic of the whole gun help to pin down the time period and if the half cock notch should be left there?

Rich Pierce, were you questioning operator ability or messing up a period correct lock? I wasn't sure.

Eric Krewson · « **Reply #22 on:** December 10, 2021, 08:22:52 PM »

You can solder paste a piece on your trigger bar, I have done it several times and never had one come off, this add on only has a few of pounds of pressure on it when you pull the trigger. I also polish the contact point on the bar and the sear to a mirror finish.

This is on the precarve from $#*! gun with a 3/8" web, I had to stop inletting the trigger plate any deeper when I started breaking into the ramrod hole. I had to do the add on to get the trigger bar to hit the sear.

D. Taylor Sapergia · « **Reply #23 on:** December 10, 2021, 08:26:13 PM »

If you eliminate the half cock notch altogether, you can reduce the outside dia of the tumbler, but it is likely hardened and tempered so will have to be annealed first to do that. I would not take metal off the outside of the tumbler as there isn't going to be a half cock notch if you do, just two full cock notches. Although the half cock notch is not a safety, ie: don't trust your life to it, it does offer some safety compared to not having it there at all. As an example, I don't like the idea of priming a pan at full cock, and then snapping the frizzen closed. The dog would definitely have to have been engaged.
I think your best bet is to fill the full cock notch with a metal shim and JB Weld to reduce the contact of the narrow sear's nose and the too wide full cock notch.
This lock has had the bridle removed for clarity to show the engagement of the sear and tumbler notches.
And where the trigger is pinned to the stock relative to the sear arm also plays a big part in how much creep a lock has before the cock falls. How about a photo demonstrating that?

Mike Brooks · « **Reply #24 on:** December 10, 2021, 08:38:06 PM »

This appears to be a lock from the rifle shoppe. Why is the back side brass plated? I have used this lock 2X and neither one had a tumbler bridal. This lock was a lock intended for military use. Hence the AR stamp. It is supposed to have a crappy trigger pull by design. The hammer fall time is incredibly slow but typical of all locks this large. This gun is never going to be fast or be a wing shooting gun.

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Author Topic: Lock help (Read 4605 times)