Whether you are restoring a classic wheelgun to its former glory or fine-tuning your target grouping, upgrading or replacing your Smith & Wesson revolver rear sight assembly is one of the best investments you can make.
However, finding the right match isn't just about picking a part off the shelf. To ensure your revolver holds its zero perfectly, you must precisely match your revolver model, barrel length, and rear blade height.
In this comprehensive guide, we break down exactly how to identify your specific Smith & Wesson model and choose the correct rear sight assembly to get back on target.
How to Find Your Smith & Wesson Revolver Model Number
Before looking at blade heights, you need to know exactly which S&W model is sitting on your bench. Because Smith & Wesson has produced dozens of iconic wheelguns over the decades, relying on appearance alone can lead to ordering the wrong part.
Fortunately, finding your exact model number is incredibly simple:
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Ensure the firearm is completely unloaded.
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Press the cylinder release and swing out the cylinder.
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Look inside the frame crane/yoke cut.
Right there on the frame, uncovered by the open cylinder yoke, you will see the model number stamped into the metal (for example, MOD 19-4 or simply 29).
Note: Smith & Wesson officially introduced this model numbering system around 1957–1958. If your revolver only has a serial number on the bottom of the grip frame and no model number in the yoke, it likely predates 1957.
S&W Rear Sight Applicability & Blade Height Chart
Once you have your model number and have measured your barrel length, use our master application chart below to find your correct rear blade height. Matching these specifications perfectly is crucial for keeping your factory point-of-aim (POA) and point-of-impact (POI) aligned.
| Model Applicability | Barrel Length | Rear Blade Height |
| Model 14 | 6" & 8 3/8" | .126 |
| Model 15 | 4" | .106 |
| Model 16 | 6" | .146 |
| Model 17 | 6" & 8 3/8" | .146 |
| Model 18 | 4" | .136 |
| Model 19 | 2 1/2" | .146 |
| Model 19 | 4" & 6" | .146 |
| Model 25 | 6 1/2" | .146 |
| Model 25-5 | 4", 6" & 8 3/8" | .126 |
| Model 27 | 3 1/2" & 5" | .126 |
| Model 27 | 6" & 8 3/8" | .146 |
| Model 27 | 8 3/8" | .160 |
| Model 28 | 4" & 6" | .136 |
| Model 29 | 4" & 6 1/2" | .146 |
| Model 29 | 8 3/8" | .160 |
| Model 34 | 2" & 4" | .086 |
| Model 43 | 3 1/2" | .086 |
Why Blade Height Matters for Your Trajectory
A common mistake is assuming any K, L, or N-frame rear sight will work across all barrel lengths.
Because different barrel lengths affect the sight radius (the distance between your front and rear sights) and different calibers carry distinct ballistic trajectories, Smith & Wesson carefully engineered specific blade heights for individual configurations. Installing a .160 blade on a revolver that requires a .126 blade will throw off your elevation tracking, forcing you to max out your adjustment screws just to get close to zero.
Ready to Restore Your Sight Picture?
Don't let a chipped blade, a missing detent ball, or a frozen adjustment screw keep your favorite revolver sitting in the safe. Upgrading to a fresh, crisp rear sight assembly restores your confidence at the range and preserves the long-term value of your firearm.
At USA Guns And Gear, we specialize in sourcing high-quality, reliable factory-spec replacement parts for classic and modern wheelguns alike.
👉 Browse our complete selection of Smith & Wesson Rear Sight Assemblies here to find the exact match for your Model 19, 27, 29, or classic target revolver today!
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