Smith & Wesson Rear Sight Plunger Models 39 59 439 539 639 459 559 659 Factory OEM 063780000

Smith & Wesson Rear Sight Plunger - Factory OEM Part

This is a genuine Smith & Wesson factory OEM rear sight plunger for 2nd and 3rd Generation semi-automatic pistols. Part number 063780000 is a critical component that secures the rear sight to the slide and provides the spring tension necessary for windage adjustments.

Product Specifications

• Manufacturer: Smith & Wesson
• Part Number: 063780000
• Condition: Factory New
• Compatibility: Models 39, 439, 539, 639, 59, 459, 559, 659, and more (see full list below)
• Function: Rear sight plunger/detent
• Material: Steel
• Weight: 0.1 oz

Compatible Models

This rear sight plunger is compatible with the following Smith & Wesson semi-automatic pistol models:

2nd Generation (Model 39/59 Series):

• Model 39 - 9mm, single-stack, alloy frame
• Model 439 - 9mm, single-stack, alloy frame, improved
• Model 539 - 9mm, single-stack, steel frame
• Model 639 - 9mm, single-stack, stainless steel
• Model 59 - 9mm, double-stack, alloy frame
• Model 459 - 9mm, double-stack, alloy frame, improved
• Model 559 - 9mm, double-stack, steel frame
• Model 659 - 9mm, double-stack, stainless steel

3rd Generation Models:

• Model 1006 - 10mm Auto, stainless steel
• Model 3904, 3906, 3944, 3946 - 9mm compact variants
• Model 4506 - .45 ACP, stainless steel
• Model 5903, 5904, 5906 - 9mm full-size variants
• Model 645 - .45 ACP, stainless steel

About This Part

The rear sight plunger is a vital component of the adjustable rear sight system on Smith & Wesson semi-automatic pistols. This precision-manufactured plunger fits into a hole in the slide and applies spring pressure against the rear sight body. This spring tension serves two critical functions:

1. Sight Retention: The plunger keeps the rear sight securely seated in the dovetail cut on the slide, preventing it from shifting or moving during firing and handling.

2. Windage Adjustment: The spring pressure allows the rear sight to be adjusted for windage (left/right) by tapping it with a sight adjustment tool or brass punch. The plunger provides resistance that holds the sight in the adjusted position while still allowing precise movement when needed.

Without a properly functioning rear sight plunger, the rear sight can shift during recoil, causing point of impact changes and accuracy problems. The plunger must provide consistent spring pressure to maintain zero while allowing windage adjustments when needed.

A worn, damaged, or missing rear sight plunger can cause the rear sight to shift position, move during firing, or fall out of the dovetail. Replacing it with a genuine Smith & Wesson factory part ensures proper sight retention and reliable zero maintenance.

Why Choose Factory OEM Parts?

When it comes to critical sight components like the rear sight plunger, using genuine Smith & Wesson factory parts ensures:

• Precise dimensions: Manufactured to exact Smith & Wesson specifications for proper fit in slide
• Reliable retention: Correct spring rate ensures secure sight positioning
• Quality materials: Proper steel composition ensures durability and resistance to wear
• Perfect compatibility: Designed specifically for 2nd and 3rd Generation pistols
• Long-lasting performance: Factory parts are built to withstand thousands of rounds
• Safety assurance: OEM parts meet Smith & Wesson's strict quality standards

Installation Notes

Installation of the rear sight plunger requires removal of the rear sight from the slide. This work should be performed by a qualified gunsmith if you are not experienced with sight installation and adjustment.

Installation overview:

1. Ensure the pistol is completely unloaded and remove the slide
2. Drift the rear sight out of the dovetail using a sight pusher or brass punch
3. Remove the old rear sight plunger from the slide (if present)
4. Install the new factory rear sight plunger into the slide hole
5. Reinstall the rear sight into the dovetail, ensuring proper alignment
6. Verify the sight is secure and properly retained
7. Adjust windage as needed and verify zero

Important: Always follow proper firearm safety procedures. Ensure your pistol is unloaded before performing any maintenance or parts replacement. Verify proper sight retention and zero after installation.

About Smith & Wesson 2nd and 3rd Generation Pistols

Smith & Wesson's 2nd Generation (Model 39/59 series, 1970s-1980s) and 3rd Generation (four-digit models, 1980s-2000s) semi-automatic pistols are renowned for their quality construction, reliability, and accuracy. These pistols feature adjustable rear sights that allow shooters to fine-tune their point of impact. The rear sight plunger is essential for maintaining sight zero and ensuring consistent accuracy. Maintaining these classic pistols with genuine factory parts ensures they continue to deliver the accuracy and reliability they're known for.

Note: This is a factory-new OEM part from Smith & Wesson. Always verify part compatibility with your specific pistol model before ordering.