The joy of repairing rear sights on S&W revolvers.

[Jeep]

In another thread some of us were talking about the difficulty of finding people trained to repair S&W revolvers. Luckily, PF has a number of members who are experts in the subject. One of them is LSP 972, who offered to send photos showing how to repair the very tricky rear sights, and Chuck Haggard has offered to post them.

[LSP972]

Let me get with Chuck, to see what will be easiest for him. I'm thinking I'll put it all in an e-mail format, that should make it simple to match up the text with the corresponding photos.

PM inbound, Chuck.

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[Al T.]

Tagged. What's a matter Jeep, that 1/2 inch wrench and a cheater bar not working on your M15?

[Jeep]

Tagged. What's a matter Jeep, that 1/2 inch wrench and a cheater bar not working on your M15?

Wait. Who told you about the cheater bar? I thought I'd removed all evidence of it.

[Al T.]

Takes one to know one.

[LSP972]

Got with Chuck, he's GTG, so I'll start working on this when I get home tonight.

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[LSP552]

It's just like owning a boat. The only thing better than owning a boat is having a friend with a boat.

[LSP972]

It's just like owning a boat. The only thing better than owning a boat is having a friend with a boat.

Fortunately for you, I'm not into aquatic activities...

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[Chuck Haggard]

Lets see if I can get this done without screwing it up.

LSP972 message follows;

Here goes; hope this works.

Text & photos:

Okay, guys, here we go; everything you wanted to know about changing the sight blade on an S&W micrometer rear sight, but were afraid to ask. First, let me apologize for the marginally-lit photos. As I was assembling the pieces/parts for the pictures, I realized that I lent my good camera with macro ring flash to my brother a while back... and he's out of town for an indeterminate period. So I had to make do with my old camera and a frigging flashlight. Oh, well...

Once you have the parts to hand, you'll need to make this tool;




That's it on the left, made from one of the adjustment screwdrivers (on the right) the factory used to include with every revolver that had the adjustable rear sight. That was a while back, so if you don't already have one, good luck finding one. You can use anything handy; its just pretty easy to make from the old screwdriver. Here's a better look;




They used to teach this in the armorer's class; this one was fabricated in 1987. Basically, you have to do some rather careful filing to get it like this. We used the hand window file in the armorer kit. That is a small, oddly shaped file used to enlarge the hand window in a frame when fitting an oversize hand. Whatever you use, make sure its a GOOD, hard file with a mill cut. You might be able to get by with one of those cheap mini files from Chinese Quartermaster (Harbor Freight) or Sears or wherever, but good luck with that.

This tool isn't absolutely necessary, but it makes the job ahead a whole lot easier- especially when it comes time to get the broken windage nut out of the sight body, and then advance the new one to the correct position. Here's how the tool fits into the windage nut;







With all our tools/parts/etc. to hand, the first step is to get the bent/broken sight blade and related parts out of the sight body. You can do this without removing the sight body from the revolver, but trust me... its easier with the body off the gun and right in front of you on a flat surface. And right here is a good place to add that you should have a screwdriver whose blade fits the slot in the windage screw properly.

Here's the components;




From the left... sight blade, windage screw, windage screw nut, detent plunger, detent plunger spring.

Turn the windage screw clockwise until it won't go any more; then continue to turn, with force (careful force!) until the screw breaks off at the nut. You'll probably feel it happen. Now peer into the tiny space between the windage screw head and sight body, and see where the adjustment detent is. Hint; the detent sits at a right angle to the screw slot. Your goal here is to get the detent wedged under the bottom edge of the sight blade; otherwise, that puppy will launch, never to be seen again, when you withdraw the blade/screw assembly from the body. Now, gently work the damaged blade/screw assembly out of the body (screw head first, or to the right, as seen when looking through the sight on the gun) and put it aside; you'll probably need to scavenge the detent plunger and spring from it in just a bit. :-)

Now, get the old windage screw nut out of there. Next take a clean toothbrush and make sure there is no accumulated crud or whatever in the sight body blade track.

Now comes the tricky part; and the trick that makes it easier. Turn the new windage screw into the new sight blade until the hole for the detent plunger and spring is midway along the bottom edge of the sight blade, and install the detent plunger and spring. This is what you should have;




Next, secure a large freezer bag. Unless you are VERY good, your first few attempts at the next step will fail, and doing it inside that bag will give you a reasonable chance of recovering the detent plunger when it launches. Put your screwdriver into the windage screw slot, depress the detent plunger with the leading edge of your thumbnail until it is flush with the side of the screw head, then turn the screw until the detent is wedged under the bottom edge of the sight blade... like this (note the position of the screw slot);




Some like to use a tool of some sort to depress that plunger, but you're already juggling several itty-bitty parts at once, so... whatever works for you.

Once done, slide this entire assembly into the sight body, as far as it will go. The screw head should be flush with the outer edge of the body. Now thread the windage nut onto the exposed threads of the screw from the other side of the body until it is also flush.

Finally, you'll need to stake the nut to the screw. Several ways to skin that cat, but the best I've found is to use a finishing nail set or bluntly-pointed awl. Don't get retarded with the hammer, because you can warp the sight body if you hit too hard. Your goal here is to immobilize the nut so it turns with the screw; otherwise, it WILL unscrew itself, with predictable results.

And that's it. I hope this was of some help, and feel free to fire away with any questions here in this thread.

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[jh9]

Brownells sells the spanner bits, but they have poor reviews.

http://www.brownells.com/gunsmith-to...prod25408.aspx

Not used these myself, but they're at least in stock. Might need to shorten the legs a bit, reviews look right about them being too long.