I want a combat sight on my old 66

[jmoln]

Note the first picture where I have taken a 66 F-Comp (which I sadly no longer have but that is beside the point), removed the existing factory sight and installed a C&S rear sight.

The next picture is my 66-3 with the old style rear sight removed showing just one hole versus three for the newer style. C&S only makes one rear sight and while I could drill and tap new holes the old hole is too close to the new one to get a clean new shot.

So my question is this - has anyone successfully had a smooth combat sight like the C&S design installed on an old frame? I looked at D&L Sports and their sight also requires all three holes.

Any ideas?

 

[SAFireman]

Try this link...they have combat sights

Smith and Wesson K, L, and N Frame Sights

 

[jmoln]

I looked at D&L already. You can see that they use the three-hole pattern that exists on all newer frames that have the rounded front end. C&S sights have two holes and use the first and third holes. The point is both these vendors' sights are made to fit the existing three hole pattern. The problem is that the older style has only one hole and it almost touches the location of the front hole. It is less than a full diameter from the new pattern. Thus if I tried to drill and tap a new hole it would break through the old hole. The C&S sight would only be able to use one screw at the back of the frame. The D&L might work with only two screws but it wouldn't look good.

So I'm looking for another creative answer for a smoother sight.

The other alternative is that since I have two of these 66-3's I could keep one original and trade out the other for a newer K or L frame but I was hoping to not break up the pair.

 

[scooter123]

I've drilled and tapped a 1988 vintage 67-1 and 1992 vintage 617 no dash to the new hole pattern and the old hole for the sight was NOT an issue. Concern for hitting the rear of the barrel with the tap was an issue, so I shifted the entire pattern 0.025 inch to the rear. For my needs, that shift won't ever be a problem.

I know you think these holes may overlap, take a look at the pic I snapped of my 67-1 with the new and old sight mounting holes. With the mentioned 0.025 inch bias you can see there is a good amount of seperation. BTW, you'll note I was originally was going to over tap the old mounting hole but changed my mind. Glad I did, that would have been totally dumb and nothing standard would have fit that oddball pattern.

I'll also note that you have to know what your doing when you tap these holes, break that tap in the hole and it'll probably cost 100 buck to have it removed via EDM machining. BTW, the hole size that S&W uses is a #6-48, not at all common however these taps can be purchased from Brownells. In addition to the tap you'll want a #2 center drill, 0.114 inch diameter drill, a 0.119 diameter ream, tapping fluid and a pin vise to hold the tap. I used a vertical mill with a DRO to do the work on my guns and that made it very easy. However, you can do it by hand if your very very careful to prick punch each location, then center punch it, and follow up with center drill, drill, and ream. Note, a prick punch is basically a center punch reground to a needel tip so you can place that prick perfectly on some scribbed lines, then you use that prick dimple to center the center punch to form a dimple the center drill will track. BTW, the reason for this sequence is to insure that a drill doesn't "walk" on you.

Now for the dimensions for the pattern used on the newer guns. Note, these dimensions include that 0.025 inch shift mentioned previously. All dimensions are from the vertical face of the notch cut into the top strap that the adjustable sight nests into. The dimension for the front hole is 1.750 inch from that face to center. The dimension for the middle hole is 1.150 inch from that face to center. The dimension for the rear hole is 0.485 inch from that face to center.

 

[duketbrd88]

Could you loctite a set screw in the old hole before you drill the new one? Just a thought!

 

[jmoln]

Thanks guys - this tells me that a new hole pattern can be produced and scooter, don't worry about my shade tree metalworking skills. If I do this it will be with a competent gunsmith or I may even send it to S&W. I had the Master Revolver Action Package done to my first 66 and the results were beautiful.