Author Topic: lock-trigger problem  (Read 5678 times)

Offline Michigan Flinter

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lock-trigger problem
« on: September 16, 2012, 01:14:46 AM »
Greetings to all. I have a problem you might help me solve? Just finished another southern looking rifle it has a large Siler flint lock and a set of Davis triggers. My problem is if I set the front trigger first and then cock hammer to halfcock I can pull the trigger and it will cycle __IF I cock the hammer to halfcock and then set the trigger it will not cycle . I haven't done anything yet but suspect  it is the adjustment on the trigger springs ?All your suggestions are welcomed please stay on subject. 

Offline Bob Roller

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Re: lock-trigger problem
« Reply #1 on: September 16, 2012, 01:27:29 AM »
 WHAT is not "cycling"?The rotation of the hammer or the
  action of the set triggers?
I was just looking at some old posts from 2008 on the
Forum and saw where some self appointed expert was saying I used
L&R or Davis tumblers in my locks. That has NEVER happened at
ANY point in time.I have posted more than once about my low
opinion of foundry quality controls on small, critical lock parts and my
disdain for them is well known to anyone who knows me.

Bob Roller

Offline Acer Saccharum

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Re: lock-trigger problem
« Reply #2 on: September 16, 2012, 01:34:30 AM »
Uh, Bob, what's that got to do with the guy's problem?

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Offline Acer Saccharum

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Re: lock-trigger problem
« Reply #3 on: September 16, 2012, 01:42:56 AM »
I'm a little mystified.

If the set triggers are cocked, the lock should drop full into half cock. The triggers should not be able to fire the lock. (bad thing to try on a regular basis, as you may break the sear nose off.)

But you are saying the lock will fire in this state? It must mean that the sear is not entering half cock completely. This may be due to some wood interference in the lock inlet. Or the lock parts bind when the lock screws tighten the lock into the inlet. You should check that first.

Try the lock function with the triggers out of the gun. Set the lock on half cock, and push up with a screwdriver on the sear bar. Should not trip the lock. If you now try to put the set trigger unit back in(with the trigger set), and it won't bottom completely, then it's touching the sear, which it should not do.


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Offline Don Getz

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Re: lock-trigger problem
« Reply #4 on: September 16, 2012, 03:03:00 AM »
Michigan....some of your terminology is confusing, similar to your problem.   You state that you can "set" the front trigger.
By that, do you mean that you have pulled the rear trigger, thereby setting the front trigger?  After doing this you can
pull the cock into half-cock, and it  will fire by touching the front trigger?   If it does this, your triggers are too high in the
stock and won"t allow the sear to fully engage the half cock notch.   If this is the condition, then you would not be able
to put the lock into full or half cock unless you set the trigger first.  This condition can be corrected, but without seeing
it, it is difficult to tell you how..........Don

Offline Bob Roller

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Re: lock-trigger problem
« Reply #5 on: September 16, 2012, 05:39:17 AM »
 Nothing really but it was fresh in my train of thought so I
added it on. That odd problem with the triggers was not
the inspiring thing.

Bob Roller

Offline Dave B

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Re: lock-trigger problem
« Reply #6 on: September 16, 2012, 05:42:37 AM »
so if I under stand you, you are testing to see if your triggers will trip when the gun is in the half cock position.  the front trigger must be allowed to travel through a few degrees to allow the rear trigger to set. if the front trigger is blocked by the sear bar then the rear trigger cant be cocked. Does Your last statement imply the triggers wont release?
« Last Edit: September 16, 2012, 05:44:35 AM by Dave B »
Dave Blaisdell

Offline Michigan Flinter

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Re: lock-trigger problem
« Reply #7 on: September 16, 2012, 04:10:14 PM »
I will try to explain my problem again.I'm not the best wordsmith around.the lock has the frizen open ,cock is all the way down,I pull back on the rear trigger to set the front,put the cock on halfcock,close the frizen pull the front trigger and the cock will move forward and strike the frizen NOW THE OTHER WAY I pull the cock back to halfcock close the frizen pull back on the rear trigger to set the front one then PULL THE FRONT TRIGGER nothing happens .I hope I have explained it better this time? What would cause this ?Thanks for your responce.

Offline Dave B

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Re: lock-trigger problem
« Reply #8 on: September 16, 2012, 05:12:42 PM »
I think Don's thought is correct and the triggers are inlet deep enough to keep the sear bar from dropping down to allow full engaugement You will need to bend up the sear bar to give enough room for the sear to engage. it will look like this when done.


Dave Blaisdell

Offline Bob Roller

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Re: lock-trigger problem
« Reply #9 on: September 16, 2012, 05:33:53 PM »
 I think that it is better to reduce the height of the release bars on the triggers
rather than risk a broken sear. My locks have sears made from 0-1
and oil hardened. I try to leave the sear arm so as to MAYBE allow
for this idea of a bent sear but still think it's a bad idea to bend these
parts when a slight modification of the triggers would suffice.
Careful measuring and pre-planning will help eliminate such problems to begin
with.

Bob Roller

Offline Acer Saccharum

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Re: lock-trigger problem
« Reply #10 on: September 16, 2012, 05:52:28 PM »
It sounds like to me, in the UNSET position, the rear trigger bar is not allowing the sear to drop fully into the halfcock notch. The trigger mainspring is forcing that rear trigger so high up that the sear can't travel far enough to engage the halfcock notch completely.


Try this: loosen the screw that holds the tension on the TRIGGER mainspring, this is the spring that fires the set trigger. even if it doesn't have enuff bang to trip the lock, you will see if the lock goes into full half cock with the trigger set AND unset.

If that works, then you can add a little trigger mainspring adjustment screw a little ahead of the mainspring hold-down screw. Then you can adjust until the triggers fire the lock and allow safe operation of the lock completely independent of the state of the set triggers.
« Last Edit: September 16, 2012, 05:53:12 PM by Acer Saccharum »
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mjm46@bellsouth.net

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Re: lock-trigger problem
« Reply #11 on: September 16, 2012, 05:54:27 PM »
Before you go through the exercise of bending the sear bar, try shimming the trigger plate in the trigger plate mortise, which will lower the trigger to see if this helps. Shim it in the front, shim it in the back and shim it front and back. It likely is only a little off if it is holding on full cock. If this doesn't work start looking for binding or wood clearance problems.

Offline Acer Saccharum

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Re: lock-trigger problem
« Reply #12 on: September 16, 2012, 05:55:20 PM »
An additional thought: in the current state, the trigger may also not allow the sear to drop into the full cock notch completely. It may cause the gun to go off accidentally, or if bumped a little too hard.
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Offline Acer Saccharum

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Re: lock-trigger problem
« Reply #13 on: September 16, 2012, 06:06:20 PM »
Try my suggestion of lightening the trigger mainspring pressure first, because you don't need to remove any metal or bend anything to try it out.
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Offline Michigan Flinter

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Re: lock-trigger problem
« Reply #14 on: September 16, 2012, 09:01:46 PM »
Thanks for all your suggestions Acer I think I will try your suggestion first and go from there .

snowdragon

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Re: lock-trigger problem
« Reply #15 on: September 16, 2012, 11:17:42 PM »
I agree with Acer. I would adjust the spring screw for tightness first, play around with it. If that worked, I would either shave down the rear trigger blade,  add a washer under the spring, or install an adjustment screw under the spring.  You can't leave the spring screw loose.  I would only bend the sear arm if I had to take too much metal off the trigger blade. If you bend the sear arm, you may need to open up the hole in the lock mortice.  Good luck. Bill