686 adjustable rear sight

Tysers · #1 01-11-2013, 12:33 AM

I just bought one of our old sevice revolvers from work. Took off the grips to clean underneath then. Figured why not under the rear sight to. Easy to come off not so easy to get back on. How do you reinstall the rear sight?

BLUEDOT37 · #2 01-11-2013, 02:12 AM

For me, the tricky part is getting the elevation nut level & square to the slot. The sight has a slight bow to it so you have to tip the front up a tad (& hold your mouth just right) to get it to slide back in the groove.

Tysers · #3 01-11-2013, 12:16 PM

I'm missing that square nut. That's my prob. I must have lost it when I took the rear sight off. I'm ordering a new rear sight for the gun. The old one is pretty beat up. Will the new rear sight have the square nut with it?

BLUEDOT37 · #4 01-11-2013, 04:08 PM

If you ordered a completed rear sight, as shown in my attachment, it will have all those parts, except the forward screw. Did you measure the old blade height & order the same size?

correction addeded

Tysers · #5 01-11-2013, 05:55 PM

No sir I have not. But I still have the old sight and can measure it. I was hoping it would be easier. Just order a S&W rear sight and it would be the measurement you needed. Do I need to take the blade out to measure it or can I measure it in the sight?

BLUEDOT37 · #6 01-11-2013, 08:43 PM

Quote:

Originally Posted by Tysers

But I still have the old sight and can measure it. Do I need to take the blade out to measure it or can I measure it in the sight?

If you have a caliper you can try measuring the existing blade from the side slot. When I tried this with my 686 I got a reading but felt it was off, so I disassembled the blade & found that the reading was indeed slightly off. (I ordered the replacement back in Oct-12. Called S&W today & it's still backordered & they still don't have a ship date !?.) You have to break the windage screw (the nut is staked onto the screw), by adjusting the blade fully to the right, until the screw breaks (it's designed to do this). I read that S&W only uses four different blade heights on it's modern revolvers: 0.126", 0.146", 0.160", and 0.196" blades, with or w/o white outline, so yours should be near one off these.

clarification:
The easiest way to remove a S&W rear sight blade is to break the windage screw. You do this by turning the windage screw CW until the blade stops against the right side of the sight, then turn it further until the head breaks off the screw's body. (If you turn the screw CCW it's harder to get the screw/nut out.) Don't loose the tiny detent pin & spring in the screw head when you remove it from the housing, as you'll need to reuse them if you're replacing the blade (kit) only. The screw head & blade come out the right side & the nut/screw come out the left.

Tysers · #7 01-12-2013, 02:21 AM

Thanks for all the info. It's been a great help.

imashooter2 · #8 01-12-2013, 06:40 PM

Break the screw turning clockwise. If you break it off with the sight blade to the left, you won't be able to get the nut off without a drill. Be careful when removing the screw head. There is a tiny spring loaded plunger that will disappear if you don't capture it. Disassembly and reassembly in a clear plastic bag is cheap insurance.

There are 2 types of revolver sights for reasonably modern revolvers. A square tang and a round tang. Did you buy the right style?

Tysers · #9 01-12-2013, 07:09 PM

Boy I hope I did. I ordered a rear sight for 4-6 bbl from brownells. But it doesn't say anything about the tang.

imashooter2 · #10 01-12-2013, 08:46 PM

Round:
http://media.midwayusa.com/productim...550/550865.jpg

Square:
http://media.midwayusa.com/productim...221/221031.jpg

Tysers · #11 01-13-2013, 01:00 AM

Mine had the square tang but brownells add didn't say if it was a square tang or round tang. Guess I'll just have to fined out when the part comes in.

BLUEDOT37 · #12 01-14-2013, 06:37 PM

Quote:

Originally Posted by Tysers

Boy I hope I did. I ordered a rear sight for 4-6 bbl from brownells. But it doesn't say anything about the tang.

I got a complete rear sight for my 325NG from Midway. They get it from S&W, from what I see, as I suspect Brownells does too. Mine had the elevation nut & it's shown on the S&W parts diagram, so I think you'll be good.

Tysers · #13 01-15-2013, 01:21 AM

Boy I hope. We will fined out in a couple days.lol!

BLUEDOT37 · #14 08-07-2013, 04:52 AM

I just replaced my second rear sight blade (kit). The first time I broke the screw by turning it CCW. It is harder to get the blade out this way because they're still screwed partly together. This time I did it CW & it's a lot easier to get the blade & nut/screw out this way as they're not screwed together, though it is a little harder to get the broken screw head out because the blade is to the right & over the screw head slot. Don't loose the tiny detent pin & spring in the screw head (put the gun in a gallon zipbag when you remove it from the housing in case it tries to fly off) as you'll need to reuse them if you're replacing the blade (kit) only. The screw head & blade come out the right side & the nut/screw come out the left.

Jul · #15 08-07-2013, 05:38 AM

Far as I know the square tang is no longer sold. If the sight is good just replace the Rear Sight Elevation Stud that holds it on. Midway and Brownells have it. I have had used ones in the past and the mounting hole was in different locations.

dant · #16 08-07-2013, 04:28 PM

a little trick ( aside from using a large plastic bag to catch all the flying parts) is when you try and reinstall,, center the plunger and its hole directly UNDER the flat of the blade after you screw on the blade till the head is flush with the end of the screw...look, you will "see" what I mean when it comes to that time.....never lost a plunger yet doing it this way......same holds true if you can get the nut off without having to "break" off the head of the screw, all depends on how good the "staking" job was done, they can and will unscrew "sometimes"

Gotta have a sturdy "split" screwdriver for the slots in the nut, and hold the opposite one, in place, or vice versa............

BLUEDOT37 · #17 08-07-2013, 07:02 PM

Quote:

Originally Posted by dant

Gotta have a sturdy "split" screwdriver for the slots in the nut, and hold the opposite one, in place, or vice versa............

I forgot to add it to my last post, but FWIW, I "sacrificed" an old 1/4" drive, 1/8" flat tip bit, that I filed out the middle to make an inexpensive "forked wrench" to turn the windage screw nut with.