Keep your AR-15 buffer system running correctly with the Colt AR15A4 Buffer Retainer Spring – Part #160308111, a genuine Colt small part designed specifically for AR-15, AR-15/M4, and M16 platforms. This OEM spring is engineered to work with the buffer retainer to control the buffer in the receiver extension, helping the rifle cycle as intended. Brownells Deutschland+4AmmoMart+4Great Gun Parts+4
OEM Colt AR15A4 Buffer Retainer Spring – What It Is
This part is listed by multiple distributors simply as “AR15A4 Buffer Retainer Spring” or “Buffer Retainer Spring for Colt AR15-A4”, under Colt manufacturer part number 160308111 (often cross-referenced with Colt Mfr. No. SP61694). Brownells+4Brownells+4Yellowstone Armory+4
Manufacturer: Colt
SKU / Product No.: 160308111
Mfr. No.: SP61694 (also described as “SPRING, BUFFER RETAINER”) Brownells UK+2Brownells Deutschland+2
Category: Rifle part – buffer / recoil system component
Because it’s a factory Colt small part, dimensions and tension are set up for Colt-spec AR-15 lowers and compatible buffer assemblies.
Role in the AR-15 Buffer System
The buffer retainer and spring sit in the lower receiver and hold the buffer in place inside the receiver extension until the upper is closed and the rifle is in battery. APEX Gun Parts+2Shooting Surplus+2
This tiny spring is responsible for:
Providing upward pressure on the buffer retainer plunger
Keeping the buffer from moving forward when the upper is pivoted open
Helping ensure that the buffer and bolt carrier group stay correctly aligned as the rifle cycles
Brownells UK and other retailers describe it as a “crucial part designed specifically for the Colt AR15-A4,” whose job is to maintain proper function of the buffer system. Shooting Surplus+2Brownells UK+2
Compatibility – AR-15, AR-15/M4, and M16 Platforms
Product specs repeatedly list the AR15A4 Buffer Retainer Spring 160308111 as compatible with common AR variants: Brownells Deutschland+3AmmoMart+3Great Gun Parts+3
Platform: AR-15 pattern lowers
Models: AR-15, AR-15/M4, M16, and Colt AR15-A4 markings
Make: Colt / AR-15 “common parts”
If you are:
Replacing a worn or weakened buffer retainer spring
Completing an AR15A4 lower build with Colt-spec parts
Maintaining a Colt AR-15, AR-15/M4, or M16-style rifle
…this OEM spring is designed to drop into the standard buffer retainer pocket in the lower receiver, alongside the appropriate buffer retainer pin.
Material & Construction
Multiple parts suppliers list this as a steel spring, built for durability in a reciprocating buffer system. Blackstone Shooting Sports+2Ammunition for Sale+2
As with most Colt small parts, it’s made to strict dimensional and material standards, and many listings note “Made in USA” in the specifications section. Brownells UK+1
Use Cases – Maintenance, Repair, and OEM-Correct Builds
Because it’s a small but important component, the AR15A4 Buffer Retainer Spring 160308111 shows up across a few typical use scenarios:
Routine maintenance & repair – Replacing tired or damaged buffer retainer springs that no longer hold correct tension.
Colt-correct builds – Builders who want a true Colt-spec AR15A4 or M16-style rifle often prefer OEM small parts labeled with Colt SKUs like 160308111. Brownells+2AmmoMart+2
Parts stocking – Gunsmiths and armorers keep spare retainer springs on hand because of their small size and critical role in the buffer system.
Replacing this spring is part of keeping the buffer assembly reliable, especially on rifles that see frequent field stripping, training use, or high round counts.
Installation & Fit Notes (General Guidance)
Retailers list this as an AR-15 “common part” for buffer systems, and it installs in the standard lower-receiver pocket for the buffer retainer: AmmoMart+2Brownells UK+2
The spring sits in the drilled recess in the lower receiver.
The buffer retainer pin sits on top of the spring.
When the receiver extension (buffer tube) is threaded in correctly, it captures the retainer head while allowing it to move up and down under spring tension. APEX Gun Parts
Always follow recognized AR-15 armorer procedures, ensure the firearm is unloaded and safe, and use appropriate tools when installing or replacing buffer system components.
Why Use Colt OEM Instead of Generic?
Several catalogs highlight this part specifically as “AR15A4 Buffer Retainer Spring – Manufacturer: Colt”, distinguishing it from generic AR-15 springs. Brownells Deutschland+4AmmoMart+4Great Gun Parts+4
Benefits of sticking with OEM specification:
Known compatibility with Colt AR-15 / M16 pattern lowers
Consistent tension and length designed around Colt buffer systems
Easy part-number reference (160308111 / SP61694) for future maintenance logs
Whether you are working on a Colt-marked rifle or simply prefer Colt-spec parts, this spring matches the dimensions used in factory builds.
Key Features – AR15A4 Buffer Retainer Spring 160308111
Technical Specs (At a Glance)
This small component is easy to overlook, but having a properly spec’d buffer retainer spring is part of keeping the AR-15 buffer system functioning smoothly and reliably over the long term.
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