doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Gunsmiths, how is this done?

This is a Southgate ejector cam located in the action bar. It has a thin flat spring that seems to be shaved off the long body of the cam. How is this done without leaving a kerf?

Im not sure in your case because I dont have the part in hand, but has yours been repaired? Ive seen a lot of European doubles that have springs dovetailed into parts, mostly on sears and cocking levers. One way they could also achieve this is to make the part long, then bend the part in half creating the spring portion onto the cam, essentially making a very large bodied v spring. In the picture it looks like your part has been pieced together or repaired, or am I just not seeing it correctly?

Looks broken to me. My buddy Ken Owens says springs can't be repaired.

In the days when such thing were forged I imagine the spring part would have been cut away with a chisel, thus leaving no kerf. This would have been done before the part was heat treated. I take it yours is broken and you want to make a new one.

Yes,

It is broken across in the middle. The little spring seems to have been shaved off from the main body. If this is true the chisel or cutting tool had to be quite thin and very hard.
The piece broke right at the base of the spring, where it was the thinnest. The spring is not as elastic as one would expect a regular spring. One can bend it at the base a little so I suspect the steel is not really spring steel, but rather lower carbon steel.
The spring could have been cut from the oposite side and bent into a V, then hammered into the body of the cam? EDIT: Like Will suggested above.
What I did was to replace the shaved spring with a separate small V spring that rests its V in a shallow notch cut in the body of the cam.

That cut with no apparent kerf can be formed at least a couple of ways

-cut the kerf (then file/polish inside the kerf) then forge the part together (pinch it) so that the kerf is reduced to zero clearance
-form and forge (fold) the material to the point where it's faces are essentially touching at the root of the 'kerf'

finish, harden/temper etc


Cheers
Tinker

Thanks all.

What type of steel would you use? The mild steel I used is too soft and it does not harden. It should be something that takes a hardening and tempering, spring steel? Is it soft enough to be worked with files and a hacksaw?

Get out to your local auto/truck wrecking yard.
Get a piece of a very early 60's or older leaf spring - best from a truck.
That should last you for about a lifetime of spring making.



Cheers
Tinker

Something like 1084, a simple carbon steel that can be worked annealed, and then heat treated.

Try Admiral Steel.

Order a piece of W1 or O1 from Brownells. It comes in rounds or flats and is quite soft until you heat treat it. A truck or car lief spring will work fine but you'll have to anneal it before you can file or cut it. Your chisel doesn't have to be thin you just want to cut a thin piece and then bend it back where you want it. Hold it in a vice and use the vice jaw as a guide. Spring making takes a little know how. Read up on it. Then make a practice piece or two.