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Greenhorn
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i have a lyman gpr .54cal left flintlock factory made gun. it has very little use maybe less than 50 shots. i took it out to clean it and cycled the action several times. when using the set trigger it has a very weak hammer fall, wont even push open the frizzen, but when using the front trigger only it works fine. is this a trigger or a lock problem? advise? thank you irishtoo
 
Posts: 27 | Location: southwest pa | Registered: 09 February 2013Reply With QuoteReport This Post
Greenhorn
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Dont know irishtoo. My buddy has a gpr also and when you cock it back set the set trigger and squezze the front trigger it doesnt work it doesnt fall forward.Oh I know whats going on with your rifle its a lefty. Razzer
 
Posts: 3 | Registered: 29 January 2013Reply With QuoteReport This Post
Factor
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Sounds like both. You end up pushing harder on the sear when not using the set trigger, and so it sounds like the sear is rubbing on the tumbler, slowing movement of the cock. So..., your set trigger might not be "bumping" the sear hard enough, which, because it moves in the opposite manner of the front trigger, might mean it's rubbing on some wood (wood sometimes swells over time). OR something may be preventing the sear from moving as it should when bumped (again such as wood swelling or corrosion). Remove the lock and the trigger, clean them both, and carefully inspect the mortise areas to see if anything is pressing. Wood swelling is a regular problem on flint guns.

LD


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Posts: 3843 | Location: People's Republic of Maryland | Registered: 10 November 2004Reply With QuoteReport This Post
Booshway
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Only thing comes to mind is that something is rubbing or binding or otherwise interfering with the lock mainspring when you fire using the set trigger. Could be wood-on-metal or metal-on-metal.

What's your sequence for setting the rear trigger and bringing the hammer to full cock? From half cock, do you bring the hammer to full cock and then set the rear trigger, or do you set the rear trigger then go to full cock? Whichever you do, if you reverse the sequence, does it affect how fast the hammer falls? (It shouldn't make any difference, but then, you shouldn't be having this problem.)

If the trigger assembly has a small screw between the two triggers, back it out two or three turns and see if that affects the gun's behavior.

Pull the lock assembly out. It should have a small 'fly' in the tumbler to prevent the sear from catching the halfcock notch during hammer fall. Is the fly there, and does it move freely if you poke it with your finger?

Good luck with it. SCL

This message has been edited. Last edited by: SCLoyalist,


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Posts: 767 | Location: Panhandle Florida | Registered: 02 February 2008Reply With QuoteReport This Post
Booshway
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quote:
Originally posted by irishtoo:
i have a lyman gpr .54cal left flintlock factory made gun. it has very little use maybe less than 50 shots. i took it out to clean it and cycled the action several times. when using the set trigger it has a very weak hammer fall, wont even push open the frizzen, but when using the front trigger only it works fine. is this a trigger or a lock problem? advise? thank you irishtoo


Most issues can be solved by simply understanding how the parts work in relation to each other and how those parts work individually.
First lets start with a single trigger .
When you pull on a single trigger . What happens is you are creating direct leverage against the sear
Once that leverage over comes the sear spring and angle of the tumbler notch , the sear will begin to move out of the Notch . Once the sear trips the notch , you lose that part of the resistance from the tumbler notch . In that instant a person actually pulls the trigger back alittle more . Doing so is a natural consequence as out reflexes are not fast enough to react to the mechanical effect of the reduced resistance .
This is why , with a single bar type trigger , you don’t need a fly to hold the sear from the ½ cock notch as we inadvertently hold the sear off the tumbler .

Now with a double set , of which there are different kinds , , the front trigger isn’t the one firing the lock . What happens is that on a double set , the rear trigger is loaded by the trigger main spring when you pull the rear trigger it pulls the forward facing trigger bar down into a notch on the front triggers trigger bar , which is rear facing OR in the case of a target type double set ,into a notch in the top of the trigger .
The rear trigger is now held under pressure from the trigger main spring . When you pull the front trigger back . The rear trigger bar is slipped from the notch , which then cause the rear trigger par to spring up and slap the sear with enough force to pop the sear from the full cock notch .
As this is a mechanical advantage , it doesn’t hold the sear off the tumbler .. It rides along the tumbler .
As there is no resistance holding the sear away from the tumble , the sear will fall into the ½ cock notch when that notch is reached . Thus a fly is used as an interrupter. Which covers the notch and allows the sear to glide across without falling into the notch .

Now there are exceptions to this .
IE if you double set is inlet to the point where the lock will not cock and hold to a notch prior to the triggers being set . In this case the trigger can hold the sear off the tumbler and no fly is needed .
Its also most commonly referred to as a target set up because the lock cannot be fired by the front trigger alone . Again the trigger has to be set regardless as to if the double set trigger is a true target trigger or not

With a hunting type double set , which your Lyman should have , both triggers will have a trigger bar .
Thus the rear trigger bar will engage into the side of the front trigger bar
. Because they overlap each other the front trigger bar is capable of contacting the sear . In which case the front trigger can be used to fire the lock when used in the unset position .
The thing both trigger types have in common is that in order to work properly , there has to be a space between the sear and the triggers . In other words there has to be travel .
Now let me also note that you can build a rifle with no travel to the double set . But that wont be the case with the Lyman .

So lets address the first issue of the lock dragging when the set trigger is used .IE set . But not dragging when the front trigger is used . IE un set .

The only way I can see this happening when the trigger is set ,
A) that the sear and tumbler are not polished . So basically as the sear spring holds the sear on the tumbler it creates enough friction to slow the lock
B) you have a issue with the fly . IE it may have a small burr on it which tries to catch the sear and slows the lock OR as is the case with a lot of Lyman locks because they use a soft plate for a bridle and thus subject to warping , the fly is being aloud to wedging the sear and slowing the lock because there is just enough outward movement of the fly . Which most often on Lyman locks , is the result of a bent bridle .

FIX. Remove your lock . Cycle it a few times . Make sure that the sly doesn’t move in and out . It only moves forward an back . Make sure that there is no jump or catch as the sear slides past the fly . If either happens then you need to touch up the edge of the fly .
Next hold the sear away from the tumbler by apply pressure to it with your thumb so that it will not catch the full cock notch . Slowly work the cock back . All you should feel is resistance from the main spring . If you feel like you have to pull alittle harder in a given spot . The look closely at where that’s happening . Most likely cause will be a warped bridle plate .

The 2nd poster who stated that the gun would fire when the triggers were unset . But not fire when the triggers were set .
First we have to know a couple things
A) does the lock fully cock without the triggers being set .
If so , then when you pull the front trigger , you hear a metallic CLICK !!!. But the lock doesn’t fire ..
That click sound is the sound made by the rear trigger as it disengages the front trigger and springs up .
If that’s the case . The cause is one of two things IMO .
a) the trigger isn’t inlet deep enough for the rear trigger bar to contact the sear when it springs up
b) the rear trigger doesn’t have enough energy being transferred to it to disengage the sear .

I find (b) to be the most common. the reason for this is that a lot of times shooter feel that its to hard to pull the set trigger . So they back out the trigger main spring retaining screw to far .
Also for what ever reason sometimes the retaining screw will back out on its own and needs to be tightened back down .
In both cases the result is the same . IE not enough energy to pop the sear from the full cock

Now onto the 2nd possible issue
B) the trigger is inlet to deep and the lock will not cock unless the trigger is set . Yet it will not fire unless a lot of travel is applied to the front trigger .
I have found this to happen with lyman and other production guns because they often put a negative angle on the full cock notch for liability reasons .
Because the system is not matched and the triggers are inlet to deep , we then end up with an issue where the rear trigger can not slap the sear once tripped . What then is happening is the sear is overriding the trigger main springs ability to trip the lock .
So the front trigger must then be pulled to the point that it levers the sear out of the full cock notch
This is very dangerous . Because you now have two triggers that are capable of firing the lock .
The front you have control over . But the rear you don’t once it has been disengaged from the front trigger notch .The slightest bounce or jar can cause the sear to move . Once it starts to move the trigger spring can then take over and the lock will fire when your not intending it to do so just yet ..

FIX
For A) take the triggers out and make sure the trigger main spring screw is tightened all the way down tight
For B) remove the trigger and place a spacer under the front an rear of the trigger plate so as to lower it .
 
Posts: 687 | Location: Payette ,Idaho | Registered: 23 November 2004Reply With QuoteReport This Post
Booshway
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PS .
The small adjustment screw , between the triggers , adjusts the angle of the front trigger .
This change in angle changes the depth that the rear trigger engages the front trigger notch .
If it gets turned in to far , the rear trigger may not fully engage the notch. Thus making one think the have set the trigger when in fact they have not .
The other thing it can do is raise the front trigger to the point that it starts to adjust the depth the sear engages the full cock . In which case the lock may not hold in full cock OR come to full cock at all
With the older GPR’s this could be an issue . But those produced after 2008 unless the screw has been changed , It shouldn’t be an issue because Lyman shortened the length of the adjustment screw so as to keep the shooter from adjusting the triggers to what they felt was a dangerous point
 
Posts: 687 | Location: Payette ,Idaho | Registered: 23 November 2004Reply With QuoteReport This Post
Greenhorn
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thanks for all the advise. i stripped it down. the bridle looked like someone hammered it and it was bent. i straitened it and stoned it smooth. the fly was flopping all over, the leg was fine point mic at .075 at the widest but the hole is .095. what was left of the fly leg snapped off. ill order another and try again. this gun has not been used that much to wear it down. again thanks
 
Posts: 27 | Location: southwest pa | Registered: 09 February 2013Reply With QuoteReport This Post
Greenhorn
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when i get a new fly ill strip it down again and look over the trigger.
 
Posts: 27 | Location: southwest pa | Registered: 09 February 2013Reply With QuoteReport This Post
Greenhorn
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That is amazing..Can you post some images of it if possible..?
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Posts: 1 | Registered: 19 February 2013Reply With QuoteReport This Post
Greenhorn
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still waiting on parts
 
Posts: 27 | Location: southwest pa | Registered: 09 February 2013Reply With QuoteReport This Post
Greenhorn
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parts came, put in a new fly, and it works well. sparks fine with set trigger or front trigger only. ill shoot it soon
 
Posts: 27 | Location: southwest pa | Registered: 09 February 2013Reply With QuoteReport This Post
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