Mainspring question

[wvmtnman]

I have an older reproduction (45 years old) that rarely set off the cap.  Is there any way to revitalize the mainspring?  If not, anyone who is able to make one??
       Thanks, Brian

[smylee grouch]

Call Cabin Creek.

[Angus]

Might look at your nipple for issues and to ensure the length is sufficient.

[Top Jaw]

If you know the maker, someone in here may have an old stock replacement.   
Second, if you locate a copy of track of the wolf catalog, they have actual size photos that you can compare measurements to your spring for an existing replacement.   I also agree with a nipple replacement. Sometimes the end can become masked out and the cap is not seating all the way down.

BH 

[rich pierce]

There are cob-job fixes that could work while you get a new spring sorted out. Not everyone has a lot of spare parts laying around but if you did, a sear spring could be divested of its tab and screw loop and wedged into the v of the mainspring. A sort of helper spring.

Generally a weak spring lacks mass somewhere. So fixing the current spring is not always possible. A trained smith could get it to forge heat and spread it a bit, re-harden, and re-temper to increase preload on the spring. This can work or just be too much stress.

[Hungry Horse]

First make sure your cap is bottoming out on the nipple. A nipple with even a small amount of distortion at its top can make a gun never fire on the first hammer fall. Chuck the nipple in your electric drill and gently releave  the top edge of the nipple.
 Most mainsprings can be retempered, but success rarely occurs on the first try. So locate another spring just in case. Metal suppliers, and welding shops, have a special crayon that only marks hot metal at a specific heat. This will help you know what when you have reached the proper tempering heat.
 You should also check the fit of the tumbler where it penetrates the plate, and the bridle, they should not bind at all.
 I kept an old CVA Mountain Rifle going for a lot of years using these tricks.

 Hungry Horse

[flinchrocket]

https://markal.com/products/tempilstik
This is the crayon that HH referred to in his post.

[Steeltrap]

https://markal.com/products/tempilstik
This is the crayon that HH referred to in his post.

I learn a bunch of stuff reading on this forum.

I few more "clicks" lead me to this video which demonstrates why having more than one temp crayon is a good idea:

[Dave B]

Yur nipple is not letting your cap rest on the nipple face. Just as Hungry horse says. I had one that would only fire the second time around. Touched up the nipple and bag

[Daryl]

Once a nipple gets peened on it's top edge, especially when the hammer's cup doesn't hit it squarely, the peening (enlarging) of moving metal prevents the cap from
seating on the nipple all the way, is what the boys are saying.  Turning this "expanded" ring down allows the caps to fit the nipple again, fully seating to the detonating compound.
It really doesn't take much of a blow to set off a cap. I have seen guys put a couple woman's hair elastics on the hammer when the main-spring broke on a trail-walk and that worked
just fine.