Sear spring slot

[westbj2]

In the past when making a lock, the sear spring slot has always been problematical.  After some experimentation with shapes of the forming tool, this one seems to work best.  The end of an old tap was ground to dimensions needed and a cutting edge formed with a diamond needle file.  The slot is only .028" wide.   Best of all, the tool shows no distress or deformation after making the trial slot.  About a dozen mild hits with a hammer and the point lubricated with kerosene.
Jim Westberg



 

[pushboater]

That is one neat little tool! Thanks for sharing.

Capt. David

[bedbugbilly]

Thanks for sharing!  It looks like it worked well!   

[D. Taylor Sapergia]

The sear spring should snap into that groove nicely Jim.  ...another page to the gun building library 'how to' book.

[rich pierce]

Looks great but I want to make sure I understand.  Is the tool used as a punch, straight in?  It does not look like you chased the slot.  It must raise metal around the hole, I'm guessing? 

[Acer Saccharum]

Metal has to go somewhere. Raised up all around hole, and if not supported well, a dimple on the other side of the plate.

(note the plate shows filing finish around the slot.)

[kutter]

Metal has to go somewhere. Raised up all around hole, and if not supported well, a dimple on the other side of the plate.

(note the plate shows filing finish around the slot.)

He's using it when making a lock,,so where is the problem with the raised up metal and a possible dimple on the outside of the plate.
All will be gone with the swipe of a file and the other polishing that is done in the course of the making of the lock.

It's a great idea. Probably how many were done originally.

[westbj2]

There is a bit of metal movement around the hole as the tool is driven into the plate......but as noted a few file wipes and it is gone from the surface.  When actually doing the plate, I think a holding fixture made of Devcon Steel on a piece of steel like the trial piece would give the bottom support needed and keep the lock plate from jumping around.

It would be interesting to mount the tool on the ram of an arbor press as that would make the tool perfectly vertical while it is being driven.  But that is too much messing around.
Jim

[Bob Roller]

I use a Dremel mini saw #198 or 199 in a V mill and it works fine.

I also used and still do,a small round stud and the same idea as the mainspring
stud works fine with a lot less trouble.

Bob Roller

[Acer Saccharum]

I've used a small flat chisel with much success.

But I really like Jim's forming tool. Why not? It makes a perfect slot.