Sight dovetail modification on slide.

[Krh1326]

Hello All,

Working on an odd project.

I have a cheap .22 pistol that I am playing with. The slide is a zinc / aluminum alloy, and it has a rear dovetail cut of 10mm / .393ish. I would like to implement some Sig sights that I happen to have on hand… but they need a .268 cut. Is there a way to shrink a cut, for lack of better wording?

I am a novice with smithing and machining, but am trying to improve my skills.
I thought of cutting a piece of aluminum, to fill that large dove tail, and shape it to match slide contour. Then I figured to try to cut the smaller dovetail, into that, but am worried if I cut all the way thru or even if it comes out too thin, the fill will just fall out, and not even hold new sight in place.

Sooooooooo ….. before I do something, that I can’t undo, I’m asking if the more experienced here, have any advice?

[Cap'n Morgan]

If there's room enough, I would probably enlarge and deepen the dove tail slot in the slide to allow for a sturdier insert.
You could also reduce the sight's male dove tail - or make a "stepped" insert to put the dove tails above each other for more strength.

[Krh1326]

May I ask what is a stepped insert? I understand the first part, and I did think of that… but didn’t know “it was done”.

[deltaenterprizes]

.393-.268= .125, nice round number!
That is 1/8”!
Make a .126 shim and reduce the size of the slot by placing it in the front or rear of sight.
Locktite will help hold it in place, use the blue Locktite!
Not a high dollar gun so I would not take extraordinary measures!

[country gent]

Depending on the tools you have available make a insert to fit the slide then cut the new dovetail in the center of it. When cutting the new dovetail be gentle as it may want to move as it comes to size. you could only cut the front or rear using the one original if it matches the sight. but having the bottom filled in makes it much stronger and better looking

[beemer]

.393-.268= .125, nice round number!
That is 1/8”!
Make a .126 shim and reduce the size of the slot by placing it in the front or rear of sight.
Locktite will help hold it in place, use the blue Locktite!
Not a high dollar gun so I would not take extraordinary measures!

This is the easiest way, did it several times on old muzzle loaders with odd size dovetails.

[HWooldridge]

.393-.268= .125, nice round number!
That is 1/8”!
Make a .126 shim and reduce the size of the slot by placing it in the front or rear of sight.
Locktite will help hold it in place, use the blue Locktite!
Not a high dollar gun so I would not take extraordinary measures!

You beat me to it. A shim is an easy fix and no permanent change to the original frame size. All the work can be done with files.

[Krh1326]

Just a shim wouldn’t want to roll up and out because of upward pressure caused by sight dovetail?

[HWooldridge]

Just a shim wouldn’t want to roll up and out because of upward pressure caused by sight dovetail?

Can stake it into place.