Author Topic: Inconsistently half cocked situation (Read 7272 times)

Maurice · « **on:** September 05, 2016, 06:56:05 PM »

My large Siler flint lock does not always engage at the 1/2 cock position after gently releasing it from the fully cocked position (not firing). The situation occurs in and out of the stock. It does not occur when fully cocked and the trigger is pulled to fire the rifle. The situation can be corrected by pulling the cock to about ¼ cock and allowing the cock to snap forward. Observation prior to snapping shows the fly flush to the left side of the recess in the tumbler. With the fly in this position, the sear lip will slide right past the tumbler and fly and only engage at the fully cocked position. After snapping the cock the fly will move counterclockwise sufficiently to allow the sear to engage the tumbler at the half cock position. If the point of the fly was about 1/64 longer it looks as though it would engage the sear lip and engage at ½ cock. The situation existed from Day 1 with this lock. It was part of a TOTW kit. The fly only goes in one way. I would appreciate any comments on a fix. Did a site search on “fly” and but no results seem to fit my situation or I missed those that do.

Hungry Horse · « **Reply #1 on:** September 05, 2016, 07:15:18 PM »

If I understand you correctly, I believe the lock should never go directly from full cock, to half cock, if the fly is doing its job. When the sear is raised at full cock, and the tumbler begins to move, the fly jumps into place and keeps the sear from snagging the half cock notch. You have to go past the half cock position, and then come back to get it to catch.

Hungry Horse

Maurice · « **Reply #2 on:** September 05, 2016, 07:54:01 PM »

To clarify – I am gently lowering the cock to the fully uncocked position – I am not trying to go to ½ cock from fully cocked. Once fully lowered I cannot get it to the half cocked position, unless I snap the cock first.

Hungry Horse · « **Reply #3 on:** September 05, 2016, 07:58:38 PM »

That sounds like the fly might be a little bit too long.

Hungry Horse

Daryl · « **Reply #4 on:** September 05, 2016, 09:43:24 PM »

Yes - that is what it sounds like to me too.

frogwalking · « **Reply #5 on:** September 06, 2016, 04:29:02 AM »

Or it needs a drop of oil. I have has some frightening issues with the flys on some Spanish locks, but never on a Chambers lock. Do you know if the lock was assembled by Chambers or someone else?

EC121 · « **Reply #6 on:** September 06, 2016, 04:52:21 AM »

The bridle might be too tight holding the fly in the forward position. Try backing off the sear screw a bit to see what happens.

Jerry V Lape · « **Reply #7 on:** September 06, 2016, 08:23:39 AM »

Might it not be a poorly finished fly? Have you examined the fly and its surrounds for roughness or burrs. Is the stem smooth. I like to carefully clean up those surfaces (without causing significant dimensional changes).

greybeard · « **Reply #8 on:** September 06, 2016, 08:24:31 AM »

I just read the original post 3 times and the way I read it it seems the lock is working just as it is supposed to. From full cock it should never go into the half cock unless you let the cock full down then pull the cock back and it will engage the half cock notch?

Bob

Mark Elliott · « **Reply #9 on:** September 06, 2016, 08:50:33 AM »

I have reread the Original and subsequent post several times and still do not have a clear understanding of the problem. The word snap in the description bothers me as you shouldn't be snapping anything on a flintlock. Once you go to full cock, the fly should cover the half cock notch to prevent sear entry. If the lock does that then all is good.

Smoketown · « **Reply #10 on:** September 06, 2016, 11:25:18 AM »

Quote from: Maurice on September 05, 2016, 07:54:01 PM

To clarify – I am gently lowering the cock to the fully uncocked position – I am not trying to go to ½ cock from fully cocked. One fully lowered I cannot get it to the half cocked position, unless I snap the cock first.

It sounds like a SHORT fly. (Or, a poorly ground tumbler.)

He is having to 'snap' the lock from 1/4 cock using inertia to get the fly to swing clear of the the 1/2 cock notch.

The sear is not 'trapping the fly' when being cocked AFTER the hammer has been MANUALLY lowered.

Maurice,

You said the Siler lock is "part of a TOTW kit".

Was the lock fully assembled when you recieved "the kit" or, was the lock in kit form and you assembled the lock?

If it was a fully assembled lock, I would definitely give TOTW a call ...

Cheers,
Smoketown

Bob Roller · « **Reply #11 on:** September 06, 2016, 02:22:27 PM »

Quote from: Smoketown on September 06, 2016, 11:25:18 AM

Quote from: Maurice on September 05, 2016, 07:54:01 PM
To clarify – I am gently lowering the cock to the fully uncocked position – I am not trying to go to ½ cock from fully cocked. One fully lowered I cannot get it to the half cocked position, unless I snap the cock first.

It sounds like a SHORT fly. (Or, a poorly ground tumbler.)

He is having to 'snap' the lock from 1/4 cock using inertia to get the fly to swing clear of the the 1/2 cock notch.

The sear is not 'trapping the fly' when being cocked AFTER the hammer has been MANUALLY lowered.

Maurice,

You said the Siler lock is "part of a TOTW kit".

Was the lock fully assembled when you recieved "the kit" or, was the lock in kit form and you assembled the lock?

If it was a fully assembled lock, I would definitely give TOTW a call ...

Cheers,
Smoketown

My experience says it's a short fly. Been there and done that and it's
usually caused by not paying attention to what I was doing.

Bob Roller

EC121 · « **Reply #12 on:** September 06, 2016, 03:07:57 PM »

I just replaced a short fly on an old(1985) Davis lock. Don't know if it was worn or just too short, but it would only go in the full cock notch. The point of the fly was level with the tumbler, and it just rode over the notch.

oldtravler61 · « **Reply #13 on:** September 06, 2016, 03:49:18 PM »

If it was my lock I would call Jim Chamber's. Just see what he thinks. I would disassemble the lock. Clean it an make sure there is no burrs or dirt. Then make sure it's back together correctly. So easy to miss the smallest details. Just my opinion.

Maurice · « **Reply #14 on:** September 06, 2016, 04:58:14 PM »

To the responder’s questions and comments.
•   First, Smoketown’s interpretation of the problem situation is exactly correct.
•   Lock parts are squeaky clean and adequately oiled.
•   The lock was fully assembled when it came with the kit – do not know who assembled it for TOTW.
•   Regarding the “short vs long” fly comments - as best as I can tell with my magnifying glass the point of the fly coincides exactly with the radius of the tumbler – the fly neither extends beyond the curve nor lies short of the curve.
•   Regarding the poorly ground tumbler comment - it seems that if the tumbler had slight bevel the width of the notch that the fly rests in, the sear would “trap” the fly and engage the ½ cock position.
Since I cannot lengthen the fly it looks like needle filing a bevel in the tumbler might solve the problem - (makes the fly longer in relation to the tumbler curve)
Any comments on this approach before I start out on that path.

Long John · « **Reply #15 on:** September 06, 2016, 05:29:34 PM »

Maurice,

I have read your post several time and it sounds to me like the lock is working EXACTLY like it should. On every Chambers lock I have used, and I have used a bunch, if I bend the lock to full-cock and then try to ease the lock to 1/2 cock the fly doesn't allow the sear to engage. Its doing its job! I have to allow the cock to fall beyond the 1/2 cock position, down to what you have called 1/4 cock, and than bend the cock back up to 1/2 cock. That's the way its supposed to work. From your description I don't think there is anything amiss with the fly on your lock. I think that those who are suggesting there is haven't understood what's going on - or I haven't.

Best Regards,

John Cholin

Daryl · « **Reply #16 on:** September 06, 2016, 07:48:31 PM »

Quote from: Maurice on September 05, 2016, 06:56:05 PM

My large Siler flint lock does not always engage at the 1/2 cock position after gently releasing it from the fully cocked position (not firing).

The sear should never engage 1/2 cock from full bent position. The fly should prevent that from happening, just as John C. said.

EC121 · « **Reply #17 on:** September 06, 2016, 08:00:52 PM »

A new fly is about $9 for the lock. It isn't that complicated. The point of the fly should extend a bit past the edge of the half cock notch for the sear nose to push it out of the way for half cocking. It should then snap forward to cover the half cock notch when advanced to full cock. It should never catch the half cock notch when released from the full cock position. The fly should move freely in the fly cut out. If the fly nose is level with the tumbler it is too short. A bevel on the edge of the half cock notch might work, but I would try another fly first. The lock I just replaced the fly in had the exact same problem, but I didn't want to mess with beveling the tumbler notch.

Smoketown · « **Reply #18 on:** September 06, 2016, 09:50:18 PM »

Quote from: Maurice on September 06, 2016, 04:58:14 PM

Any comments on this approach before I start out on that path.

Muarice,

Please call TOTW ...

If it IS a "Jim Chambers Lock" it probably has a guarantee!!

Cheers,
Smoketown

Ky-Flinter · « **Reply #19 on:** September 06, 2016, 10:41:20 PM »

Maurice,

I would suggest calling Jim Chambers directly http://www.flintlocks.com/ He can probably tell you from the markings on the inside of the lock (or lack of markings) who assembled your lock.

I would do this before taking a file to your lock. Altering the lock will very likely void any warranty.

-Ron

Ky-Flinter · « **Reply #20 on:** September 06, 2016, 10:52:27 PM »

Some of you guys aren't "listening".

Maurice is NOT trying to go from full-cock directly to half-cock. From full-cock he is slowly lowering the cock all the way to rest, then taking the cock back to half-cock, where it SHOULD hold, but it does not. He has found that if he allows the cock to fall from about 1/4 bent, it will set the fly such that he CAN THEN engage the half-cock notch.

-Ron

M. E. Pering · « **Reply #21 on:** September 07, 2016, 04:05:30 AM »

I think there could be a couple of problems here. Fly geometry is the first that comes to mind... It is too short, or the angle on the fly is under-centering it from the pivot. Second, the fly could be sticky for a number of reasons: There might be a burr interfering with it's proper function, or it is extremely sticky at it's pivot, but this is unlikely. The only other thing I can imagine is a very weak sear spring, since it is the pressure of the spring that activates the fly. Is the sear spring screw tight? It should be, and there should be no evidence of it scraping the lock plate. Another area to check is inside the bridle where the fly rides. Any burrs in there? But I think it is more likely that you have a bad fly, which is ground such that it doesn't snap back to where it should be to allow you to enter half-cock.

Matt

Long John · « **Reply #22 on:** September 07, 2016, 04:30:26 PM »

All,

My mistake! Thanks, Ron for knocking me in the head - I needed that!

It sounds as if the fly is "sticking" in its recess. The pulling of the cock to 1/4 bend and letting it snap down is jarring it enough by simple inertia to allow the fly to get unstuck, as I understand you.

There are two possibilities one is a bur in the fly or the fly recess that is impeding the free rotation of the fly once forced to the edge of the recess. the other is a warp of the pin on the fly relative to the flat of the fly.

If you call up Chambers Flintlocks I suspect that they will ship you a replacement tumbler and fly. The other option is to take some 600 grit abrasive paper and polish the fly and tumbler to get smooth operation.

Best Regards,

John Cholin

PPatch · « **Reply #23 on:** September 07, 2016, 04:59:30 PM »

"• Lock parts are squeaky clean and adequately oiled."

Jim Chambers recommends keeping your "fly dry," no oil or other lube in that area.

Also, As others have mentioned, your next best bet is to have a conversation with Jim before you file or otherwise alter the lock.

dave

Maurice · « **Reply #24 on:** September 07, 2016, 06:22:50 PM »

To all who have responded

Based on all the comments and my observation of the fly and tumbler in a similar Chambers flint lock, it looks like a longer fly is the solution. So, I am going to opt for the simple fix and get a new fly from Jim Chambers. After I receive the new fly, I will post whether it solved the problem (or changed it). Look for the post “ Half cocked update”. In meantime, thanks for the suggestions.

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Author Topic: Inconsistently half cocked situation (Read 7272 times)

greybeard

Smoketown

Smoketown