The adjustable rear sight that Smith & Wesson uses on its revolvers is an engineering marvel. Designed to sit on the topstrap in a shallow milled groove, it’s fully adjustable for both windage and elevation. Unlike some other adjustable revolver sights, it sits fairly low and usually doesn’t project high enough to cause most folks any problem with it snagging on their clothing or holster. In addition, the adjustments for windage and elevation are easily made with the large slotted adjustment screw heads. With spring-loaded detents, audible clicks can be heard and felt as you adjust the sights. I’ve always thought of it as a darn nice sight. In fact, for many years, one of the really slick modifications to the 1911 .45 ACP pistol was to install one of these revolver sights on the slide.
As a gunsmith, I’ve seen quite a few S&Ws come through my shop. In many cases, the problems were caused by the owner, and they often involved the rear sight. Sometimes the owner had dropped the gun and damaged the sight. Usually, it was just a bent or broken sight blade that could be replaced fairly easily. Other times the owners wanted me to switch the rear sight blades, either install a white-outline blade or a plain black blade. Those were quick, simple jobs -and moneymakers for the shop.
Many S&W owners are hesitant to work on or modify the rear sight, but it really shouldn’t scare them off. As I said, it’s fairly simple. In addition, replacement factory sight blades and related parts are readily available from Smith & Wesson and various parts suppliers, such as Brownells. And another company -Weigand Combat Handguns Inc.- offers an unusual rear blade that dramatically improves the sight picture by extending back over the factory rear sight base so the shooter sees a large, uncluttered flat sight.
Just keep in mind that to swap out the sight blade you first have to break the sight! That sounds pretty awful, but it’s nothing to worry about. The factory sight is designed with the windage screw staked in place, and normally it’s not removable. In order to remove and change the sight blade, the shaft of the windage screw must be broken. The folks at Smith & Wesson designed the windage screw with a very thin unthreaded portion of the shaft directly behind the screw head. That’s the part that’ll break or twist apart easily.
Before I get into the mechanics of changing out the sight blade, you need to be aware that the sight contains some very small components, all of which can be easily lost. The head of the windage screw is drilled to accept an extremely small spring-loaded detent. This holds the windage screw in place and accounts for the “clicks” you hear and feel when adjusting the sight. Be very careful that these small parts are not lost. I always work on the S&W sight over a clean, clutter-free Ransom bench mat so I can keep track of these small parts.
I recently picked up a nice old S&W K-Frame .22 revolver made back in the 1950s. It’s a great shooter and just the ticket for informal recreational shooting. Unfortunately, with the ammo and sight picture I’m using, I have to use quite a bit of the elevation adjustment. Because of that, I decided to install a slightly higher rear sight blade. The Weigand sight blade was not only a bit taller, but it also provided a cleaner, less-cluttered look with the rear face of the blade.
Out with the Old
How to Replace a Smith and Wesson Rear Sight Blade: While you can remove the entire sight assembly, I opted to leave it on the revolver while I changed the sight blade. I did dismount the cylinder so that I could clamp the revolver in my padded bench vise.
Once the revolver was secured, I used a properly fitted Brownells screwdriver bit to turn the windage screw to the right (clockwise) until the blade was moved as far to the right as possible. I continued to apply pressure to the windage screw until the head of the screw twisted off the threaded shank. It didn’t take much pressure.
With the windage screw head still in place in the sight base, I then pushed the sight blade to the left and exposed the windage screw nut, which was staked onto the screw shank. With the nut extending out beyond the sight base, I was able to turn it with my fingers until it was freed from the blade and then pulled from the left side of the sight base. The blade was then pushed back to the right, where it moved the windage screw head out of the sight base. Be very careful when doing this so you don’t lose the little detent and spring. With the screw head removed, the blade was then pulled to the right and out of the sight base.
In with the New
It’s a good idea to run the new windage screw into the sight blade before installing it in the sight base. By lubricating the screw and running it into the blade, you can remove any burrs and make the movement of the blade on the screw much smoother and easier. Also, keep in mind that the screw is steel and the blade is aluminum, so you want to ensure there’s enough lubrication to prevent any galling of the threads.
With the new sight blade installed on the windage screw, the spring-loaded detent was placed in the screw head and then pressed into the sight base. The windage screw nut was then turned onto the screw shank and staked in place. When staking the sight nut, the right side of the sight base was firmly supported on a nylon bench block. I used a specially ground Brownells staking punch to spread metal from the end of the windage screw shank into the two slots of the nut.
That’s all there was to it. It’s a very simple installation and well within the capabilities of most hobbyists.
By the way, if you must drill out the windage nut for any reason, use a #38 drill. Do not drill to a depth of more than 0.100 inch. Any more than that and you could go through the nut and damage the sight base.
With my new sight I have a nicer sight picture, and I use less of my elevation adjustment. It should make shooting my old S&W .22 even more enjoyable.
Until next time, good luck and good gunsmithing.