Fine tuning a trigger for accuracy?

[melsdad]

What can I do to make my trigger pull smoother, and to lighten it up some. I have a Lyman trade Rifle, I have no idea what the trigger pull poundage is from the factory. I am certain some stoning is involved, but am not sure where to start. Pictures or a tutorial would be great.

Thanks

[Sir Michael]

Remove the trigger and the lock and polish the surface of the trigger that moves against the sear and then polish the surface of the sear that the trigger moves against.  That will make it as smooth as possible the trigger pull can only be changed by relocating the trigger pivot point closer to the sear bar.  

You might also want to completely disassemble the lock and polish every surface that is against another metal surface.  If there are any visible wear points polish the part that is making the mark until it doesn't.  Inletting Black is good for finding wear points that haven't made themselves obvious yet.

[Hank in WV]

You can lighten the pull by grinding the sear spring a little narrower and thinner. Grind in the direction of the spring and not across it. Be careful and go slow. Then put a high polish on it. Also, do this on the part after the bend.

[Pichou]

Hi,

I was told to take the lock out, and try it, then take the sear srping off and try the lock again in your hand.  Also move the trigger with the lock out any of thos things can make it hard you don't want to work on one without knowing about the other things.  But polish is always good  

[RichW]

Hi,

I was told to take the lock out, and try it...

Who on earth told you that???
 :rotf  :rotf  :rotf

Oh, I did?

[Pichou]

Wiseguy hmmm?  Nyuck nyuck nyuck

[Old Salt]

You can lighten the pull by grinding the sear spring a little narrower and thinner. Grind in the direction of the spring and not across it. Be careful and go slow. Then put a high polish on it. Also, do this on the part after the bend.

Hank,

The sear spring on a Lyman lock is a very small coil spring.  About all you can do is compress it a little and then give it a try.  If you compress it too much the nose of the sear won't engage the tumbler with sufficient force to be safe.  Of course you can then just stretch it back a little.  

Salt

[melsdad]

Old salt, when my lock is in the full cock position the coil spring looks completely compressed. What else can be done with this spring?

[melsdad]

Here is a picture of it in the half cock position.

[melsdad]

I have stoned and polished all of the mateing surfaces of the lock assembly, and I can feel a big difference in the triggers smoothness. However the trigger pull itself still seems to be quite heavy. Is there something else that can be done to lighten the trigger pull without any major modifications to the lock?

[Old Salt]

Melsdad,

I can't see the picture when I'm at work. :?  

Without seeing your photo I think you have displayed the main spring on the Lyman lock.  You can't do anything to that spring to better trigger pull.

Salt

[melsdad]

O.K., I understand what spring you mean now, sorry I am still learning all of the parts and there proper names. When I had the lock apart for stoning, and polishing, I didn't pay much attention to this spring.

[Old Salt]

O.K., I understand what spring you mean now, sorry I am still learning all of the parts and there proper names. When I had the lock apart for stoning, and polishing, I didn't pay much attention to this spring.

No need to be sorry, your curiosity is a positive trait.

I've read posts where people cut a portion of one coil off the sear spring to get a lighter trigger pull.  Just be very carefull whatever you decide to do.    

If there is not enough pressure exerted from the sear spring when the lock is at full cock the lock can be caused to fire with very little pressure on the cock.  Basically the sear nose does not fully engage the tumbler notch so it is easily knocked out of the notch.

You can percieve the danger presented with a loaded and primed rifle.  

Salt

[Sir Michael]

Before you go cutting or messing with the sear spring I'd examine the interface between the sear and the tumbler.  Observe very carefully what the tumbler does as you raise the sear bar.  You may need to use a magnifying glass and a good light to see what's going on.  If the sear has to rotate the tumbler before releasing it you can fix this by straightening the face of the full cock notch on the tumbler.  Also look at how far the sear has to move before releasing the tumbler.  You may also need to remove some of the excess material from the outer perimeter of the tumbler.  You may also see that only a small portion of the sear actually touches the tumbler.  This needs to be made square to the tumbler.

Just a couple of thoughts. :lol:

[melsdad]

Don't worry, I had no intentions of cutting the spring. The spring is what gives the cock the energy to strike the frizzen correct?

The way the sear and the tumbler are now in relation to each other, as far as angle goes. The sear does have to rotate the tumbler a bit to release the cock. The way the angles are now the sear is sort of captured in the tumbler at full cock. I thought of changing this angle to more of a 90° instead of the roughly 80° angle that it is now. this way the sear would only have to slide off of the face of the tumbler instead of having to push it out of the way as it is now.