Keep your rifle running like a factory-built Colt with the Colt AR15A4 Bolt Catch Spring – Part #160308104, a genuine OEM small part that delivers consistent tension and reliable bolt catch operation on AR-15, AR-15/M4, and M16 platforms. This steel spring is a direct Colt component, built to precise specs so your last-round lock-back and manual bolt hold-open work exactly the way they should. Blackstone Shooting Sports+2Frisco Guns+2
OEM Colt Bolt Catch Spring – Built for Reliable Function
The AR15A4 Bolt Catch Spring is listed by multiple retailers and Colt distributors as a factory part for the AR-15 family, carrying SKU 160308104 and described simply as the Colt AR15A4 Bolt Catch Spring. Brownells+2Frisco Guns+2
Manufacturer: Colt
Model / Type: AR15A4 Bolt Catch Spring
SKU / Product Code: 160308104
Often referenced by wholesalers as “SPRING, BOLT CATCH” under Colt’s internal manufacturer ID. crowwholesale.com+1
Using true Colt OEM hardware helps ensure that the spring rate, length, and diameter are matched to the original design of your lower receiver and bolt catch, reducing the chance of timing or lock-back issues that can crop up with out-of-spec aftermarket parts.
What This Spring Does in Your AR-15
The bolt catch spring is a deceptively small but essential part of the AR operating system. Together with the plunger and bolt catch, this spring:
Provides consistent upward tension on the bolt catch, so it can properly engage the bolt face when the magazine follower lifts it on an empty mag Blackstone Shooting Sports+2Brownells UK+2
Helps ensure reliable last-round bolt hold-open, an important cue for reloads and safe handling
Supports smooth, repeatable operation when you manually lock the bolt to the rear for inspection, administrative handling, and range procedures
Colt’s own and dealer descriptions emphasize that this spring is “an essential component for ensuring the reliable operation of your AR-15 platform,” designed to keep the bolt catch working smoothly over the long term. Brownells UK+2Brownells Österreich+2
Steel Construction & Colt-Level Quality
Several product listings identify the Colt AR15A4 Bolt Catch Spring as a steel spring with a natural/silver finish, built for longevity in a high-cycle part of the rifle. Blackstone Shooting Sports+2Frisco Guns+2
Material: Steel coil spring
Finish / Color: Typically listed as silver or standard spring finish (ideal for internal receiver use) Blackstone Shooting Sports+1
Durability: Brownells UK and Nordic sites highlight it as made from high-quality materials for long-lasting performance. Brownells UK+1
Brownells’ European descriptions explicitly note that this Colt spring is made in the USA and describe it as a “vital component” for reliable AR-15 and AR-15/M4 function, reinforcing its role as a real, duty-grade part—not generic hardware. Brownells Österreich+2Brownells Norge+2
Broad Platform Compatibility – AR-15, AR-15/M4, M16
Retailers like AmmoMart, Frisco Guns, and Brownells list the AR15A4 Bolt Catch Spring as fitting:
If your lower is built to standard AR-15 spec, this spring is designed to drop into the bolt catch recess and work with OEM-dimension bolt catches and plungers without fitting or modification.
Ideal for Maintenance, Upgrades & Colt-Correct Builds
Because it’s a genuine Colt component with a low cost and high impact on function, the AR15A4 Bolt Catch Spring is a smart choice for:
Routine maintenance & refreshes – replace weak or worn springs to restore crisp bolt hold-open performance
Colt-correct clone and retro builds – keep small parts as authentic as the rollmark using factory Colt hardware crowwholesale.com+2Brownells Österreich+2
Armorers & gunsmiths – stock OEM springs as part of a standard AR-15 parts kit to quickly fix rifles that no longer lock open reliably
Dealers often market it as a “must-have for serious shooters and gunsmiths” and emphasize that it’s perfect for both upgrades and basic repairs. Blackstone Shooting Sports+2Brownells UK+2
Easy to Install – Standard AR-15 Procedure
The AR15A4 Bolt Catch Spring uses the familiar AR-15 lower receiver layout and is straightforward to install if you’re comfortable working on your rifle:
Ensure the firearm is unloaded and safe.
Place the spring into the bolt catch recess on the left side of the lower receiver.
Insert the bolt catch plunger on top of the spring.
Align the bolt catch and carefully drive in the bolt catch pin to capture the assembly.
Brownells and other retailers note that it’s simple to replace, making it suitable for both professional armorers and hobby builders who follow proper AR-15 armorer practices. Brownells UK+1
Key Features – Colt AR15A4 Bolt Catch Spring 160308104
Technical Specifications (At a Glance)
Brand: Colt
Product Name: AR15A4 Bolt Catch Spring
SKU / Code: 160308104
Manufacturer ID: SPRING, BOLT CATCH (listed by Colt distributors) crowwholesale.com+1
Platform: AR-15, AR-15/M4, M16
Category: Lower receiver parts → Bolt catch components
Material: Steel
Weight (shipping): 0.005 kg (approx.)
If you’re serious about keeping your AR-15 or Colt-pattern rifle in top mechanical condition, the Colt AR15A4 Bolt Catch Spring 160308104 is a small investment that helps protect one of the rifle’s most critical functions: consistent, reliable bolt lock-back.
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