Lock slipping

[pdt1793db]

So a while ago I had a Pecatonica Tennessee Mountain Rifle kit built for me with a Siler lock. Took it out shot approximately three rounds. Load the fourth, try to bring it to full ****, and bang it goes off. Really glad I had it pointed down range at the time. Anyway, thought it was dirt or something, clean the gun, and adjust the set trigger screw. Lock still slips when placing slight forward pressure on the hammer. It does this when I take the lock out of the rifle also. So my question is. What do I do about this? Do I need to strip the locks internal parts and start over?

 

[Pete G]

First check to make sure that there is no interference between the sear and the stock, the bottom of the hole for the sear arm especially. This can keep the sear from fully engaging.

 

[Col. Batguano]

As what Pete said, as well as the trigger slot. Make sure everything moves freely that actually should. This time of year wood will be as swollen as it's going to be and some binding is likely happening. Certainly wood is more so now than towards the end of winter.

 

[pdt1793db]

I'm pretty sure the stock is not the issue but I'll check it when I get home. This morning I removed the lock, brought it to half ****, pressed forward on the hammer and no issues. I then brought it to full ****, pressed forward on the hammer and it went off. So regardless of the stock its slipping in full **** without the sear being engaged.

 

[Phil Coffins]

The sear and / or the tumbler full **** notch are not square. Even with minimal sear spring pressure the lock should stay at full **** if the surfaces are properly shaped. You state that the lock is clean but recheck these points then if necessary stone the engaging surfaces to make them sharp and square and at the correct angles. Also make sure the sear screw isn’t over tightened. If in doubt have this done by a smith.

 

[Flintleather]

I second the sear screw tightness, sometimes if over tightened the sear will drag and wont engage in the tumbler notches. Flintleather

 

[Zonie]

With the lock out of the stock, move the sear by pressing up on its arm. It should move easily with the only resistance coming from the sear spring.
With the sear moved so that it is not pressing against the body of the tumbler, closely look at the edge of the sear that engages the tumbler notches. It should be sharp and have no chips in it.

With the lock set to full **** you should be able to clearly see the sear engaging the tumbler full **** notch.
Closely examine the edge where the full **** notch meets the outer surface of the tumbler. It should be a sharp edge with no chips.

If it is at all rounded off the lock will need a new tumbler. (I don't recommend that people without the proper training should try to reshape or sharpen the full **** notch.)

Wh

 

[pdt1793db]

Great advise Zonie. I'll check it out and let you all know what I find. Might post some pics. Thanks again.

 

[Grenadier1758]

Zonie said what I would have said only Zonie probably said it better. Really check out the nose of the sear where it engages the tumbler.

 

[Darkhorse]

Before doing anything to the lock I would call Jim Chambers and tell him what's going on. That lock should still be in warranty. I'd rather have a lock fixed by a Master than one just "Fixed" out of luck.

 

[pdt1793db]

That is a good thought I will do that.

 

[Don Steele]

First....If this is a Chambers lock, send it to Jim.
I had a Chambers large Siler that was behaving a lot like you describe. In that case...Turned out the fly was too short. The nose of the fly had been polished by the rifle builder with the idea that it would function better (I suppose). Got it just a hair too short. Jim took a quick look, tossed me a new fly... fixed it right up.

 

[LRB]

Ahh, please explain to me how a too short fly has anything to do with sear engagement at full ****.

 

[Don Steele]

Sorry, I can’t. I’m not sufficiently well trained to provide that. Just passing along personal experience, not my opinion, but that of an expert in the field which might be helpful to someone experiencing a similar problem.

 

[Artificer]

Ahh, please explain to me how a too short fly has anything to do with sear engagement at full ****.

I agree with Wick, but perhaps Don meant a fly that was too LONG and that can interfere with the sear engaging the Half **** notch correctly, but would not affect the engagement of the full **** notch?

Gus

 

[Artificer]

If the lock IS good outside the stock, then it is probable the sear leg is hitting the wood in the stock and not allowing the Sear to go high enough into the full **** notch, or the set trigger/s are inletted too close to the Sear or even though very rare, the bottom of the trigger might be hitting the trigger guard.

Gus

 

[Loyalist Dave]

It does this when I take the lock out of the rifle also. So my question is. What do I do about this?

Just my 2 cents....
My hunting buddy's fowler started to do that, even OUT of the stock as yours does. Took a look...
Broken sear tip.
The sear was too brittle, and his young son had shouldered the fowler, with the lock at half **** and had pulled the trigger, thinking it was at full ****. He wasn't supposed to be handling the gun..., oh well. He put it back and it appeared to be working right.
My buddy didn't discover the problem until hunting season last year.

With the sear tip broken the remaining parts function..., but where the sear interfaces with the tumbler, it barely catches the edge of the half-**** notch, and doesn't fully go into the slot for half-**** position. So it acts as though it's at a full-**** position on the tumbler, and a little pressure causes what little friction is holding the tumbler in place, to give...., voila.... the **** falls from the half-**** position. It goes off half-cocked.

As mentioned send it back to Mr. Chambers.

LD