caplock question

[Long John]

Friends,

I usually don't shoot caplock guns so I don't know as much about them as I would like.

A friend of mine has a Lyman Great Plains rifle, purchased used some years ago.  When he tries to shoot the thing most of the time when the hammer falls the cap does not go off.  I have seen him cock and fire 6 or 7 times before the gun goes off.  The spring tension on the hammer did not feel very stout to me. when I pulled it back.

Do any of you have similar experience?  I am thinking that either the lock needs a fresh spring and/or the barrel needs a fresh nipple.  Any thoughts before I start making a fool of myself barking up the wrong trees?

Thanks,
JMC.

[MuskratMike]

Have seen this on those rifles several times myself. A new spring will fix the problem.

[D. Taylor Sapergia]

Long John:  it sounds to me like a combination of several faults.  The first is a modern coil spring that doesn't have adequate whack, so a new spring there is in order as the Muskrat says.
Secondly, it is entirely possible that the nipple needs to be addressed.  Remove the nipple, chuck it up in a drill press by the threaded end, and with a file and abrasive cloth, polish the tube of the nipple so that a cap will seat all the way down to the primer on the nipple.  I submit that then the cap will go off first crack.

[Grischi]

Investarm (manufacurer for Lymans) also made these locks with V-springs. They have a good tension. If a new coil spring isn't as desired maybe you have a chance to get a lock with the V-spring.

Christian

[Dwshotwell]

I have a CVA that I built thirty five years ago. It sat idle for several years, and when I pulled back out I had the same issue. Replacing the main spring fixed it.

[Bob Roller]

A good lock will resist the first lifting of the hammer and as the cocking progresses it will be be nearly  zero.
Taylor is a menace to low end production locks and his experience is as good as mine,
Bob Roller

[TDM]

Not sure what type of spring the lock has from your description. Old ones had Vs, newer one have coils. Either way, while your buddy is waiting for a replacement spring I’d check tumbler for any gummy residue or dirt. And sometimes the bridle screws can be too tight. Worth a look.

[alacran]

I always start with the simplest solution to a problem. Taylor is correct that nipples get buggered and need to be dressed as he describes.
That would be the first thing I would do. After that I would check to see if the hammer is making partial contact with the nipple. Striking the nipple at an angle will gall it quickly.
if that doesn't solve the problem, I would check the lock internals as TDM states. If after all that the problem persists, I would look into a new spring.

[Long John]

Friends,

Thank you for your replies.  I have my path forward!

JMC

[Hungry Horse]

 Clean the inside of the lock, lube it sparingly, turn the nipple as mentioned, and it will most likely be fixed.

Hungry Horse