Easy sight fix

[kawalekm]

The rear sight of my M1-carbine has gotten lose in it's dovetail and has started slipping side to side, with the corresponding disappearance of accuracy. My copy of Gunsmith Kinks recommended peening the edges of the female dovetail to tighten it up. Unfortunately, the sight didn't fit tight enough and still slid left and right.

Some of my other guns have a lockscrew going through the sight, so I though I'd add one to the M1 sight. The problem is that the rear sight is a peep which slides forward and back on a little ramp to change elevation. If I wanted to add a lockscrew, it would have to be low enough to allow the peep ring to ride up and down it's elevation ramp.

I drilled and tapped a 6X48 hole through the bottom of the sight.
I then cut a 6X48 screw head off and cut a screwdriver slot with a dremill tool.http://i141.photobucket.com/albums/r55/kawalekm/tappingsight.jpg

After mounting the sight, I added the lockscrew, coated with locktite, and locked it in place.http://i141.photobucket.com/albums/r55/kawalekm/mountingsight.jpg
I'll take it out next weekend and give it a test to see if the zero holds.
Michael

[OzarksJohn]

Howdy.

I remember that in my old M1 carbine armorer's book that peening was the proscribed method too. As long as that set screw isn't in the way of any adjustments it should work good. IF it doesn't hold, take a punch or drill and make a detent in the dovetail to engage the set screw.OzarksJohn

[kawalekm]

Actually, I did that too. After the hole was drilled and tapped I positioned the sight on the receiver, then center punched it through the drill hole. I then drilled a little dimple in that spot on the receiver. When screwed down, the bottom of the screw seats into that dimple.

[Pitdog]

The OTHER trick, and I have used this a lot on old .45's and also to tighten up hinge frame shotguns, is too grind an old or broken punch (which I have plenty of) to a point. Use it to just start punching into the bottom of the dovetail and it will raise the metal thereby tightening the fit. Set screws are almost always better, though in some cases I have had to do both. If the doevetail is badly worn, sometimes a set screw can push the sight up and make it sit crooked too, I have encountered this as well, in which case and dovetail file and that homemade punch come in real handy. So does a mig welder sometimes LOL