Making a new main spring for the 62 Police

[M. De Land]

While smoothing up the ratchet of the new cylinder recently fit the main spring gave out so spent most of last evening filing/grinding out a new one,hardening and tempering it.
I should have taken some pictures along the way but once I start making metal chips and filings it hard for me to stop and mess around with picture taking.
Now that I'm ready to describe how it was done I see the need for pictures to relate the more difficult areas to negotiate. One would think a one leaf, curved flat spring would be very simple but is actually quite complicated as length, curve profile and heat treat have to be correct or one starts over again.
Guess I'll go back out in the shop and take some pictures like I should have last night.
The broken spring was annealed and curve removed so I could lay the shape out on the flat spring stock which .500 wide by .062 thick.
The general shape was formed on my bench grinder being careful not to make it to small.
This spring had to have a hammer roller trough filed in the top end so it will track down center and not veer off to the side.
The trough has to start out pretty much level with the roller contact and most of the spring action is a down ward bend with very little rear ward movement. If not level when the bend is started then the tip of the spring wants to move forward and bind at the hammer purchase base ahead of the roller.
The lower spring seat on the frame is angled to tension the main spring body to the rear and also to secure the flat head screw around the entire perimeter of the purchase hole. If this is not draw up firmly against the underside of the flat head purchase screw then the spring bends through the hole and will quickly fail.
The proper profile of the bend is trial and error until it looks and feels right then the heat treat is 1500 F for about 20 minutes, quench in oil and I draw the temper using an old black smith method I pick up decades ago that has never failed me and I've made a lot of springs over 40 plus years.
Click on picture to enlarge.
One finds a flat lid of some kind, deep enough so that a 50-50 mix of 30 wt motor oil and Kerosene will cover it laying on it's side, take it out side out of the wind and lite with a propane torch. Let it burn out and it will be perfectly tempered.

 

[M. De Land]

While smoothing up the ratchet of the new cylinder recently fit the main spring gave out so spent most of last evening filing/grinding out a new one,hardening and tempering it.
I should have taken some pictures along the way but once I start making metal chips and filings it hard for me to stop and mess around with picture taking.
Now that I'm ready to describe how it was done I see the need for pictures to relate the more difficult areas to negotiate. One would think a one leaf, curved flat spring would be very simple but is actually quite complicated as length, curve profile and heat treat have to be correct or one starts over again.
Guess I'll go back out in the shop and take some pictures like I should have last night.
The broken spring was annealed and curve removed so I could lay the shape out on the flat spring stock which .500 wide by .062 thick.
The general shape was formed on my bench grinder being careful not to make it to small.
This spring had to have a hammer roller trough filed in the top end so it will track down center and not veer off to the side.
The trough has to start out pretty much level with the roller contact and most of the spring action is a down ward bend with very little rear ward movement. If not level when the bend is started then the tip of the spring wants to move forward and bind at the hammer purchase base ahead of the roller.
The lower spring seat on the frame is angled to tension the main spring body to the rear and also to secure the flat head screw around the entire perimeter of the purchase hole. If this is not draw up firmly against the underside of the flat head purchase screw then the spring bends through the hole and will quickly fail.
The proper profile of the bend is trial and error until it looks and feels right then the heat treat is 1500 F for about 20 minutes, quench in oil and I draw the temper using an old black smith method I pick up decades ago that has never failed me and I've made a lot of springs over 40 plus years.
Click on picture to enlarge.
One finds a flat lid of some kind, deep enough so that a 50-50 mix of 30 wt motor oil and Kerosene will cover it laying on it's side, take it out side out of the wind and lite with a propane torch. Let it burn out and it will be perfectly tempered.

I should have added that spring tension on this lay out can be adjusted slightly without changing spring shape or heat treat. It is accomplished by making an angled shim to fit on the underside of the screw purchase between the grip frame and underside of the spring. The shim will need an elongated hole to accommodate a slight angle. Remember the purchase threaded hole is still orientated to the original frame angle but we're using it's clearance slop in the thread to accommodate the adjustment shim. Aluminum works good for this as it will compress fit under the cap screw load and cushion the spring purchase.
If the taper is made outward then tension increases but if reversed and made inward the tension is reduced . It must be perfectly flat though either side of it's taper so the spring is sandwich gripped level under the cap screw.
I caution this because some folks like to back off the tension by loosening the purchase cap screw but this makes the spring bend through the hole and it will quickly fail.

 

[CaptainVane]

I ordered a main spring from VTI because my lil .31 is weak and adding 2nd spring keeps the hammer down preventing cap jams and weak cap misfires. I saw a video on YouTube about adding a second one to the existing which works well. Now i cant find the video on how to do it. Anyone know? , plz post link to the video. Duelist, Blackie, Eras Gone, or someone else.

 

[M. De Land]

I ordered a main spring from VTI because my lil .31 is weak and adding 2nd spring keeps the hammer down preventing cap jams and weak cap misfires. I saw a video on YouTube about adding a second one to the existing which works well. Now i cant find the video on how to do it. Anyone know? , plz post link to the video. Duelist, Blackie, Eras Gone, or someone else.

It will work better to stay with the original design and use a stiffer single spring than to double up.

 

[CaptainVane]

It will work better to stay with the original design and use a stiffer single spring than to double up.

Looked all over, utube, many threads and sites. No stiffer spring available unless your a gunsmith and can fabricate one.

 

[45D]

Looked all over, utube, many threads and sites. No stiffer spring available unless your a gunsmith and can fabricate one.

Shouldn't need one.

 

[M. De Land]

Shouldn't need one.

Yeah, good point, makes me think something else is askew.
The new one I show was made the same dimension-ally of the original except for the bend which had to be worked out but is probably pretty close and works fine.
One does have the flexibility to form more or less bend before heat treating to adjust tension strength some what.

 

[CaptainVane]

Yep, tried double spring, hammer would not cock, too much pressure but the new spring had more curve than the 20yo original. So i used that one and it snaps faster. Will see when i go to range.

 

[William P Sepessy]

I simply shorten a SAA mainspring. In one instance I had to slightly trim the width on either side of the screw to fit the one piece grip, but it wasn't much. Did it completely cure the problem? No, but the cap blowback was reduced quite a bit.

 

[M. De Land]

Yep, tried double spring, hammer would not cock, too much pressure but the new spring had more curve than the 20yo original. So i used that one and it snaps faster. Will see when i go to range.

The new spring can be annealed , the bend reshaped and the spring re-hardened and tempered as described .
One wants to make a copy of the original bend for comparison on paper before annealing and re-bending the new profile.
A helpful profiling of the bend tip is to put the new spring under the cap screw and just tighten enough to make contact with the spring above the hole and note the angle of the spring to the bottom of the grip frame. Probably needs a picture to show what is being described.

 

[Gee Dog]

For most of us, time is money. If or when I need a new mainspring I’ll just buy one from VTI for a whopping seven bucks.

 

[M. De Land]

For most of us, time is money. If or when I need a new mainspring I’ll just buy one from VTI for a whopping seven bucks.

Makes sense unless time is a constraint and a hunt or match is close !

 

[Bad Karma]

I’ve always enjoyed your posts Mike. Sometimes I think you’re picking flyspecks out of the pepper shaker but you do nice work and it’s evident that you care about it.

 

[45D]

I’ve always enjoyed your posts Mike. Sometimes I think you’re picking flyspecks out of the pepper shaker but you do nice work and it’s evident that you care about it.

Well Thanks BK !! I enjoy your posts as well and thanks for the compliment!!
My point above is just a "push" to get folks to think "what else?". The best answer isn't always "get a
bigger hammer". Would not a stronger spring moving the same payload try to move you further off
point of aim than a more "manageable" force? Precious "lock time" lost with a lighter spring can be regained by removing all the friction/ forces the mainspring has to power the hammer through on the way to ignition. Better yet, keeping the same spring and just removing the "obstacles" will free up more available force for ignition. These revolvers out of the box just have to "function" which leaves a lot of "cleanup" that can result in an amazing setup.
It works with belt pistols, horse pistols and pocket pistols.
Don't just decide to get a bigger hammer (spring!!)!

Mike

 

[Bad Karma]

Well Thanks BK !! I enjoy your posts as well and thanks for the compliment!!
My point above is just a "push" to get folks to think "what else?". The best answer isn't always "get a
bigger hammer". Would not a stronger spring moving the same payload try to move you further off
point of aim than a more "manageable" force? Precious "lock time" lost with a lighter spring can be regained by removing all the friction/ forces the mainspring has to power the hammer through on the way to ignition. Better yet, keeping the same spring and just removing the "obstacles" will free up more available force for ignition. These revolvers out of the box just have to "function" which leaves a lot of "cleanup" that can result in an amazing setup.
It works with belt pistols, horse pistols and pocket pistols.
Don't just decide to get a bigger hammer (spring!!)!

Mike

Actually I was replying to @M. De Land but it goes for you as well! So many guns are running like thoroughbreds thanks to YOUR efforts… (Now someone will tell me that DeLands Christian name is Melvin…)
I don’t think there’s a better time to be getting into cap and ball pistols than right now (except for the chronic cap shortages.) if only Colt were still around to make genuine colts using modern materials but to the standard of the originals. Maybe we’d see that Magnum Open Top!!?

 

[45D]

. . . if only Colt were still around to make genuine colts using modern materials but to the standard of the originals. Maybe we’d see that Magnum Open Top!!?

Hey, we're already knocking on the door !!

( I don't know his name either!! )

Mike

 

[M. De Land]

Actually I was replying to @M. De Land but it goes for you as well! So many guns are running like thoroughbreds thanks to YOUR efforts… (Now someone will tell me that DeLands Christian name is Melvin…)
I don’t think there’s a better time to be getting into cap and ball pistols than right now (except for the chronic cap shortages.) if only Colt were still around to make genuine colts using modern materials but to the standard of the originals. Maybe we’d see that Magnum Open Top!!?

Mortimer Snird the Third De Land, Nah it's Mike De Land but 45-D was using it first !
I just hate fly manure in my pepper !

 

[Bad Karma]

“I just hate fly manure in my pepper ! ”

It’s always so hard to know when to quit though!

 

[sussexmuzllodr]

I love to hate making springs....

 

[acavdragoon]

Actually I was replying to @M. De Land but it goes for you as well! So many guns are running like thoroughbreds thanks to YOUR efforts… (Now someone will tell me that DeLands Christian name is Melvin…)
I don’t think there’s a better time to be getting into cap and ball pistols than right now (except for the chronic cap shortages.) if only Colt were still around to make genuine colts using modern materials but to the standard of the originals. Maybe we’d see that Magnum Open Top!!?

There is a Magnum open top, that be the Walker.