S&W Model 1 Third Issue Mainspring

[tjtoolbox]

I asked this question in S&W antiques and did not get many replies. So I thought that I would try S&W Smithing.
I am trying to make a complete Model 1 Third Issue Revolver that belonged to my Father. I have a Mainspring from a Model 1 1/2. The spring looks the right width but is to long. I was told by Dave Chicoine that I could modify it to use in the gun. My Question is what is the overall length of the spring, I don't want to grind off to much and ruin the spring. I welcome any Information that the Forum Members can supply, Thanks Joe.

 

[2152hq]

I can't give you the exact length, it's a cut and try type of operation.
A template or mockup of the spring made from cardboard (business card works well) cut to the shape and then carefully put in place and at the correct angle/bend of the actual spring gives a good approximation of what the spring length should be.
Use it to cut yours a bit LONGER and then work back from there.
Always give yourself enough to work with.

A sharp, new file will cut the spring OK and will avoid the use of a grinder and it's potential to overheat things. It makes the fitting process alot easier too IMHO. You can see what you're doing better and less chance of taking off too much in one cut.


FWIW, I can tell you I've made mainsprings for the Model 1 1/2 from M&P (K) frame mainsprings in the past.
They need both length and a bit of width reduction to make them fit.
The width reduction only at the base end to make them narrow enought to fit between the grip frame straps.
The 'hooks' fit fine as-is IIRC. If anything, the overall width of the hooks may have to be narrowed a bit but I don't really recall haveing to do so.

Not quite as snappy as a real factory 1 1/2 spring but they do the job and will get a gun back into service in a pinch.

 

[tjtoolbox]

Thanks 2152hq for your info. I would not have thought of using a business card to make a templet for the spring.I do still have a good amount of excess to get rid of before doing the fit and finish.Thought that I could get a rough estimate of the length, these springs are not made anymore so asked for help.Thanks Joe.

 

[tjtoolbox]

Took the advice of 2152hq and made a pattern of mainspring, ground down mine to size and then trimmed to fit. Works Perfectly. I can not wait to shoot it. I will post results.