The Firing Pin Safety & Spring 100002733 is a genuine Glock OEM firing pin safety with spring (MFR #4543) designed to restore factory reliability and safety to a wide range of Glock pistols. Whether you’re rebuilding a high-mileage duty gun, refreshing a trusted carry pistol, or completing a custom slide build, this small part plays a big role in preventing accidental discharges and keeping your firearm running the way Glock intended.
Perfect for armorers, Glock enthusiasts, and serious shooters, this factory set gives you the original firing pin safety plunger and matching spring in one convenient package—no guessing, no mix-and-match aftermarket parts.
Genuine Glock Firing Pin Safety & Spring – Factory Correct, Factory Safe
This kit is a true Glock factory component, not a clone. That means it’s built to the same dimensions, heat-treatment, and quality standards as the parts that ship in new pistols from the factory.
Key OEM advantages:
Engineered by Glock for correct timing and engagement
Ensures the firing pin stays blocked until the trigger is intentionally pulled
Maintains original trigger feel and reset characteristics
Ideal for guns used in defensive, duty, or competition roles where reliability is non-negotiable
Using OEM safety parts is one of the most important things you can do to keep your Glock safe, predictable, and true to its original design.
Wide Model & Caliber Compatibility
The Firing Pin Safety & Spring 100002733 / 4543 is designed to fit most standard double-stack Glock pistols across several calibers. Brownells and other distributors list compatibility with:
Supported Glock models include (check your specific pistol before ordering):
9mm: Glock 17, 19, 26, 34
.40 S&W: Glock 22, 23, 27, 35
.357 SIG: Glock 31, 32, 33
10mm Auto: Glock 20, 29
Additional listed models such as Glock 21, 30, 36 (.45 ACP) and Glock 37, 38, 39 (.45 GAP) appear in the manufacturer fit chart.
The Brownells description specifies that this firing pin safety and spring fits 9mm, .40, .357, and 10mm Glock pistols, with a make/model list that covers nearly the entire standard Glock lineup.
Because there are multiple versions of Glock firing pin safeties (including specialized parts for models like G42, G43, G43X, G48, and G44), always verify part number 100002733 / 4543 against your exact model and generation before installation.
What the Firing Pin Safety Does – Critical Internal Safety
Inside every Glock, the firing pin safety is a spring-loaded plunger that physically blocks the firing pin (striker) from moving forward unless the trigger is deliberately pressed.
Benefits of a properly functioning firing pin safety & spring:
Prevents the striker from reaching the primer if the handgun is dropped or impacted
Ensures the pistol only fires when the trigger is pulled fully to the rear
Helps maintain Glock’s reputation for drop safety and mechanical reliability
Over time, high round counts, contamination, or improper modifications can affect this component. Replacing it with a fresh Glock OEM safety and spring helps keep your pistol’s internal safeties working exactly as designed.
Durable Construction for Long Service Life
Glock firing pin safeties are built from hardened steel with a matching coil spring, designed to endure thousands of firing cycles under real-world conditions.
Construction highlights:
Hardened steel plunger for wear resistance where it interfaces with the firing pin
Precision-wound spring tailored to provide the correct upward force and timing
Factory geometry that maintains a consistent contact surface with the trigger bar
This durability is essential in defensive and duty guns that may see heavy training use and must still function flawlessly when needed most.
Restore Factory Reliability in High-Mileage Glocks
On high-round-count pistols, small internal parts like the firing pin safety and spring can:
Accumulate carbon and debris
Show wear at contact points
Develop inconsistent movement or sluggish return
Refreshing these parts with TRIGGER HOUSING W/EJECTOR 100002689 helped with ejection; similarly, Firing Pin Safety & Spring 100002733 brings the striker blocking system back to factory spec, supporting:
Consistent, positive trigger operation
Reliable release of the firing pin only when intended
Continued compliance with Glock’s internal safety design
For many shooters, replacing the firing pin safety and spring is part of a broader “small parts refresh” on guns that see serious use.
Ideal for Repairs, Parts Kits, and Custom Builds
This OEM firing pin safety & spring set is a smart choice for:
Repairing a Glock that shows signs of firing pin safety wear or sluggish operation
Building a custom slide or frame using factory internals for maximum reliability
Armorer and range parts kits, ensuring you have critical safety parts on hand
Proactive maintenance before high-volume classes, matches, or duty deployment
Because this is a complete safety + spring assembly, you don’t have to source separate pieces—just confirm compatibility and drop in the factory part.
OEM Fit – Drop-In Design (Professional Installation Recommended)
Glock designs its internal parts to drop into compatible frames and slides without fitting when used as intended. Most experienced Glock owners or certified armorers can replace the firing pin safety and spring as part of routine maintenance.
That said, because this is a core safety component, it’s best practice to:
Ensure the firearm is completely unloaded before any disassembly
Perform a full function and safety check after installation
Consider having installation and inspection done by a qualified gunsmith or Glock armorer, especially on carry or duty pistols
Correct installation helps guarantee that the firing pin remains blocked until the trigger is intentionally pulled.
Key Product Details – Firing Pin Safety & Spring 100002733
Product Name: Glock Firing Pin Safety & Spring
SKU / Brownells #: 100002733
Manufacturer Part Number (MPN): 4543
Manufacturer: Glock (OEM)
Type: Firing pin safety plunger with matching coil spring
Fit (per manufacturer charts):
Glock 17, 19, 20, 21, 22, 23, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 (verify model & generation)
Calibers Covered (per description): 9mm, .40 S&W, .357 SIG, 10mm Auto (with some .45 and .45 GAP models listed in the fit chart)
Use Case: Maintenance, repair, parts replacement, and OEM-spec builds
Why Choose Firing Pin Safety & Spring 100002733?
Choosing the Firing Pin Safety & Spring 100002733 (Glock MFR #4543) means you’re getting:
A genuine Glock OEM safety component – not an untested copy
Broad compatibility with many of Glock’s most popular pistols in 9mm, .40, .357, and 10mm
A drop-in replacement that restores or preserves factory safety performance
Durable construction designed for high round counts and real-world conditions
Peace of mind knowing your Glock’s internal drop safety system is running on factory-correct parts
For Glock owners who take safety and reliability seriously—whether for everyday carry, home defense, duty use, or competition—the Firing Pin Safety & Spring 100002733 is a small, affordable part that plays a critical role in your pistol’s performance and safety.
The End
