Percussion trigger malfunction

[caintuck rifle]

I have a Lyman Great plains rifle that is not letting the hammer fall when the trigger is pulled. I can pull the hammer to half cock and set the trigger then attempt to fire the gun but the hammer will not fall until the trigger is reset and pulled a second time. (The gun will not fire unless the trigger has been set and pulled twice every time.)
I am wondering if trigger is somehow not hitting the sear hard enough the first time and must hit it a second time to fire. Any suggestions or help would be helpful.
Thanks Y.M.H.O.S. Caintuck

 

[galamb]

First thing I would try is a simple "tune".

Set the hammer at "full cock".

Set the trigger.

Turn the little screw (between the triggers), slowly, clockwise until the the hammer falls (fires).

Back the screw out exactly one turn and see it that helps.

If that doesn't help you could have 1) a weak spring that needs replacing or some crud up in the trigger itself, but try the "tune" first.

 

[Oldnamvet]

You are trying to fire it from half cock???

 

[caintuck rifle]

That makes me feel smart meant to say "full cock"

Thanks for the help I will try that

 

[George T.]

You might want to pull the trigger assembly and scrub it with solvent and oil with a good light oil. I try not to tighten them enough to pull them deeper than required. As long as they are cleaned and oiled and tight enough not to move around I am happy and they usually work.

Geo. T.

 

[necchi]

It's the "fly".
Take the lock out, degrease it well with Brake cleaner, dry it the re-oil the moving parts, paying attention to the fly, that little piece like some good clean lube.

 

[paulab]

If the rifle fires on the second attempt all the time, your nipple could be peened. The first attempt at firing fully seats the cap on the nipple, the second attempt fires the cap. Change the nipple.

 

[sleeperNY]

If the hammer is not falling on the first set and pull and does on the second set and pull I will bet that the spring on the trigger is set to soft. Take the trigger out and see if you can tighten it up some and I am sure it will fire on the first set and pull.

Jim

 

[StewartLeach]

Summary of good advice you have received:

Remove the lock, soak with solvent and scrub well, flush and dry, lubricate with LSA, Break Free or similar. Be sure the tiny little fly is free to move.

Tighten the screws that hold the bridle- the plate that holds the other internals in place- up to just snug. Too tight adds drag. Check them frequently, if they loosen you'll have a different set of problems.

When replacing the lock in the rifle, tighten the lock bolt to the just snug setting. Too tight will cause the internals to drag on the wood in the mortise.

Adjusting the trigger let-off might help. Lyman's lawyers specified a screw too short to lift the set trigger bar far enough to release without pulling the trigger. This is known as making the trigger idiot resistant. Nothing can be made idiot proof.

White Fox, in the Peoples Republic of Boulder

 

[Zonie]

The factory screw between the triggers on the Lyman GPR is too short to release the triggers, even if it is screwed in all the way.

I think that is Lyman's or the makers attempt to keep the guns safe.

Several members have replaced that screw with a longer one they found at their hardware store.
Once that is done, it will adjust the trigger release as you described.

By the way folks: This screw does not adjust the pull weight of the main trigger. It only adjusts the distance the main trigger needs to be pulled to fire the gun.

 

[galamb]

Gotta love it when someone else decides they need to protect us from ourselves.

Wasn't aware of the short screw on the GPR

 

[rustyh]

The best thing I did to my GPR is to toss the stock trigger assembly and install a Davis Deerslayer trigger assembly in it.

 

[AZbpBurner]

Be sure that there is a clear path of travel for both sear and trigger release. I've had a couple of Lyman rifles that had residual wood within the inletting that interfered with smooth operation of the locks, there may be a little bit of wood impeding free movement between the two engaging surfaces.

If you take the time to understand how the Lyman double triggers function, and how to adjust them, there is no need to scrap them for a more spendy trigger. The trigger on my GPR was virtually non-functional when I got it, but with some cleaning ad adjustment, it was to my satisfacton less than an hour later. It doesn't take any special ability to make it work, just a little observation and patience.