Re-setting a main spring

Muzzleloading Forum

Help Support Muzzleloading Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Colin Miller

32 Cal
Joined
Nov 13, 2018
Messages
7
Reaction score
2
Location
Hawkesbury, NW of Sydney, Australia
I feel like the mainspring in one of my little percussion cap pistols need a bit more oomph to fire off the caps reliably.

There is no way I'm going to find a replacement so I think I need to reset the one I have.

I remember tempering spring steel back in high school but that is well over 50 years ago. Any advise on how to go about it would be greatly appreciated.
 
I feel like the mainspring in one of my little percussion cap pistols need a bit more oomph to fire off the caps reliably.

There is no way I'm going to find a replacement so I think I need to reset the one I have.

I remember tempering spring steel back in high school but that is well over 50 years ago. Any advise on how to go about it would be greatly appreciated.
Before you do that Colin, is there any way you can add some shims to add more tension? Another thought is to check out Dixie Gun Works catalogue.
Regards, Keith.
 
I feel like the mainspring in one of my little percussion cap pistols need a bit more oomph to fire off the caps reliably.

There is no way I'm going to find a replacement so I think I need to reset the one I have.

I remember tempering spring steel back in high school but that is well over 50 years ago. Any advise on how to go about it would be greatly appreciated.
Tempering a spring only softens it. It does not make the spring have any more power.

The force a spring makes depends on the springs width, thickness and how far it is bent.
If you want the spring to produce more force you will need to figure out a way to make it bend more.
A word of caution about doing this. The more a spring is bent, the greater the risk that the spring will break.

IMO, the best course of action is to make sure the hammer pivot screw and the place the spring pushes against the hammer are well lubricated.
Also make sure the hammer isn't rubbing or dragging on the frame as it falls. If it is, a little lubrication on the sides of the hammer might help.
 
Before you do that Colin, is there any way you can add some shims to add more tension? Another thought is to check out Dixie Gun Works catalogue.
Regards, Keith.
I've checked Dixie, nothing like it. Can't use shims either. Its a U shaped spring one end is put in tension by cocking the hammers, the other end of the spring works like a sear so the trigger releases the tension and fires the hammers. I think I need to heat it up and then open up the U, the temper it to maintain the spring function.
 
If you heat the spring up to the point it can be bent easily, it will need to be totally rehardened before it can be tempered to soften it to a good spring hardness.
Unless you know what the right temperature to heat it to before quenching is and the right way of quenching it (oil? water?) you are risking ending up with a broken spring.
 
Tempering a spring only softens it. It does not make the spring have any more power.

The force a spring makes depends on the springs width, thickness and how far it is bent.
If you want the spring to produce more force you will need to figure out a way to make it bend more.
A word of caution about doing this. The more a spring is bent, the greater the risk that the spring will break.

IMO, the best course of action is to make sure the hammer pivot screw and the place the spring pushes against the hammer are well lubricated.
Also make sure the hammer isn't rubbing or dragging on the frame as it falls. If it is, a little lubrication on the sides of the hammer might help.
Good advice. I'm thinking I need more oomph because I have 2 of these pistols. This one is very soft to cock and somewhat lazy to release compared with the other which does fire and has a very strong cocking action and really zaps down on the cap.
 
Might I suggest you make a new spring, that way you always have the original for a pattern. "Simplified V Springs" by Kit Ravenshear is a $5.99 book at Dixie Gunworks or Track of the Wolf. Dixie also sells spring material.

Not sure how well equipped your shop is, but you will need some basic tools. A keyhole saw with metal blade, grinder or file and torch will take you a long way for tools. I have made only a few springs, my dad made several more than me in his day, but has since passed. His belief was too many people wanted to overheat the spring to a bright red, I still remember him telling me cherry red is rather dull, not bright red. I quench mine in oil, but some metals are different. What Dixie sells uses oil.

Give it a try. Worst your out of is a $6 book and a $2.50 piece of metal that will likely do several springs. Just noticed where your from so shipping maybe your biggest hurdle, not sure about that one.
 
Last edited:
Might I suggest you make a new spring, that way you always have the original for a pattern. "Simplified V Springs" by Kit Ravenshear is a $5.99 book at Dixie Gunworks or Track of the Wolf. Dixie also sells spring material.

Not sure how well equipped your shop is, but you will need some basic tools. A keyhole saw with metal blade, grinder or file and torch will take you a long way for tools. I have made only a few springs, my dad made several more than me in his day, but has since passed. His belief was too many people wanted to overheat the spring to a bright red, I still remember him telling me cherry red is rather dull, not bright red. I quench mine in oil, but some metals are different. What Dixie sells uses oil.

Give it a try. Worst your out of is a $6 book and a $2.50 piece of metal that will likely do several springs. Just noticed where your from so shipping maybe your biggest hurdle, not sure about that one.
Thankyou, that's an excellent idea. I have plenty of tools and I do like the idea of keeping the original just in case.
 
If you make a new spring remember, the width of a spring effects the power of the spring on a 1 to 1 ratio. That is, if the width increases 10 pecent, the power increases 10 percent.
The thickness however has a much greater effect on the spring.
It has to do with something called the Moment of Inertia. While the width value effects the value directly, the thickness is cubed so small changes in thickness makes a BIG difference.
A typical formula for Moment of Inertia for a rectangular shape is: (bd^3)/12 or in plain language, (width times thickness^3) divided by12.
Needless to say, when a number is cubed (or multiplied times itself 3 times), it gets big, fast.
 
Colin,

I've had good luck heating a mainspring red, re-shaping and quenching in warm water.
After this it needs drawing back as it will be brittle. Drawing back or tempering I've done in molten lead.
How much is always the problem. If too much, it will be soft and bend. If not enough it will likely break.
Trying a spring when newly hardened and drawn back, is like walking through a minefield....Never sure what is going to go off!
Yes, I've broken the odd spring, but some (antique ones)that were too soft and useless are working beautifully now after being re-worked.
If you Do harden a spring, work it very carefully for a start, and feel in into half, then slowly with more working, into full cock.
If it feels too stiff, draw it back a bit more.

Good luck!
Richard.
 
It most probably is spring stock so polish it up a bit with 320 grit sand paper so you can see the color, bring to a blue color heat and then role in heat protection powder. Now bring up to a good red heat on a fire brick, cover with a pie tin and let cool to room temperature. It will be dead soft. Now bend to original shape and go through the same heating process again only this time quench in light oil or as I do in tough quench from Brownell's.
Now for the all important temper draw, I have the equipment to do it precisely in a programmable, Multi-stage electric oven but it is time consuming and unnecessary , for flat springs I always just use the old black smith trick of cutting 30 weight motor oil with kerosene 50-50 mixed well, covering the part on it's side in a flat pie tin or can lid and lighting it with a torch. Move it out side out of the wind and let it burn out on it's own. The spring will be perfectly tempered every time.
I've made a lot of gun related springs over the years and have never had this simple technique fail me.
 
It most probably is spring stock so polish it up a bit with 320 grit sand paper so you can see the color, bring to a blue color heat and then role in heat protection powder. Now bring up to a good red heat on a fire brick, cover with a pie tin and let cool to room temperature. It will be dead soft. Now bend to original shape and go through the same heating process again only this time quench in light oil or as I do in tough quench from Brownell's.
Now for the all important temper draw, I have the equipment to do it precisely in a programmable, Multi-stage electric oven but it is time consuming and unnecessary , for flat springs I always just use the old black smith trick of cutting 30 weight motor oil with kerosene 50-50 mixed well, covering the part on it's side in a flat pie tin or can lid and lighting it with a torch. Move it out side out of the wind and let it burn out on it's own. The spring will be perfectly tempered every time.
I've made a lot of gun related springs over the years and have never had this simple technique fail me.
Olde School tempering, I love it. Keep 'em coming!
 
rcflint posted this:
"To strengthen a spring, Pettifogger took another spring and cut it short, then put it under the mainspring in the Colt. By adjusting the length of the "helper" spring, he could adjust the tension of the hammer. Of course, the helper spring could only be adjusted by shortening it, so start longer than you think you need.

Pietta's Remingtons have always had too strong a spring, they are thick, and the angle of the slot in the frame is such that it pre-loads the spring too much."

Here's some examples of how folks try to strengthen their springs:

5o6yps.jpg
MVC-157F.JPG
View attachment 1027
misc015.jpg
 
I feel like the mainspring in one of my little percussion cap pistols need a bit more oomph to fire off the caps reliably.

There is no way I'm going to find a replacement so I think I need to reset the one I have.

I remember tempering spring steel back in high school but that is well over 50 years ago. Any advise on how to go about it would be greatly appreciated.
Before you go and waste your time trying to make this spring try here - <http://www.vtigunparts.com>
If you must make a spring use 1075 annealed spring steel it is very forgiving to hardening & tempering temp errors and makes a fine spring.
 
The trouble with the block up method is that it shortens the spring lever movement and thus makes less spring length to bend more and will cause premature fatigue and finally breakage.
Helper springs are useful if they do not restrict the main spring arm movement.
 
It most probably is spring stock so polish it up a bit with 320 grit sand paper so you can see the color, bring to a blue color heat and then role in heat protection powder. Now bring up to a good red heat on a fire brick, cover with a pie tin and let cool to room temperature. It will be dead soft. Now bend to original shape and go through the same heating process again only this time quench in light oil or as I do in tough quench from Brownell's.
Now for the all important temper draw, I have the equipment to do it precisely in a programmable, Multi-stage electric oven but it is time consuming and unnecessary , for flat springs I always just use the old black smith trick of cutting 30 weight motor oil with kerosene 50-50 mixed well, covering the part on it's side in a flat pie tin or can lid and lighting it with a torch. Move it out side out of the wind and let it burn out on it's own. The spring will be perfectly tempered every time.
I've made a lot of gun related springs over the years and have never had this simple technique fail me.

+1 Have made many springs in 40+ yrs gunsmithing and this method is the best I’ve used. Can’t recall having one fail. Brownells has good flat spring stock.
 
Back
Top