CMMG AR-15 Rifle Buffer / Action Spring — 55CA93F (UPC 815835013473)

Keep your rifle cycling smoothly with the CMMG AR-15 Rifle Buffer Spring (Action Spring)—a precise, durable replacement engineered to restore consistent bolt carrier velocity, reliable lock-back, and clean feeding/ejection across a wide range of loads. Whether you’re refreshing a well-used setup or completing a new fixed-stock rifle build, this CMMG spring (Model 55CA93F, UPC 815835013473) delivers dependable, mil-spec–style performance you can feel every time you press the trigger.

Why Choose the CMMG Rifle Action Spring

• Mil-spec–style geometry for predictable, repeatable cycling and proper carrier return.

• Quality spring steel for longevity, resilience, and resistance to set/creep over high round counts.

• Consistent wire temper & wind to reduce twang, harmonics, and inconsistent lock timing.

• True rifle-length format designed for A1/A2 fixed-stock receiver extensions (rifle tubes).

• Drop-in replacement for straightforward maintenance and reliability upgrades.

• CMMG quality assurance trusted by armorers, competitors, and serious enthusiasts.

Designed for Smooth, Reliable Cycling

A healthy action spring is critical to AR-15 reliability. The CMMG Rifle Buffer Spring provides the correct return force to drive the carrier forward with authority, chamber the next round, and produce consistent bolt catch lock-back on empty. Optimized spring rate and length help reduce short stroking, sluggish return, and erratic ejection that can emerge as springs wear.

Ideal Applications

• Fixed-stock rifle builds (A1/A2) using rifle-length receiver extensions and rifle buffers

• Refresh/maintenance on legacy service rifles and precision SPRs

• Duty/training carbines with fixed stocks where reliability and service life matter

• Competition & varmint rigs seeking consistent cycling across temperature and ammo variations

Compatibility Note: This is a rifle-length action spring for rifle receiver extensions (fixed stocks). It is not a carbine spring and is not intended for carbine-length receiver extensions. Always match spring, buffer, and receiver extension lengths (rifle with rifle, carbine with carbine).

Installation & Maintenance (General Guidance)

1. Unload and clear the firearm before servicing.

2. Remove the stock/receiver extension components per your armorer’s manual.

3. Inspect the buffer, spring, and receiver extension for fouling or burrs; clean as needed.

4. Insert the CMMG rifle action spring and rifle buffer into the rifle-length tube, ensuring free movement.

5. Function check: cycle the action by hand and verify smooth, unobstructed travel and positive lock-back.

Always follow manufacturer torque values and safety practices. If you’re uncertain, consult a qualified armorer.

Signs It’s Time to Replace Your Spring

• Weak lock-back or intermittent failure on last round

• Erratic ejection patterns or sluggish return stroke

• Excessive “twang” or noticeable length loss versus a new spring

• High round count service interval coming due

Technical Details

• Product: CMMG AR-15 Rifle Buffer / Action Spring

• Model / SKU: 55CA93F

• UPC: 815835013473

• Type: Rifle-length action spring (AR-15 pattern)

• Use With: Rifle-length receiver extension (A1/A2) + rifle buffer

• Material: Quality spring steel, mil-spec–style

SEO Quick Facts (For Easy Scanning)

• CMMG AR-15 rifle action spring replacement

• Mil-spec–style rifle buffer spring for fixed stocks

• Model 55CA93F, UPC 815835013473

• Compatible with AR-15 A1/A2 rifle receiver extensions

• Restores cycling reliability and consistent lock-back

The Bottom Line

If your AR-15 is due for a refresh—or you’re finalizing a fixed-stock rifle build—the CMMG Rifle Buffer / Action Spring (55CA93F) is a smart, dependable choice. It’s built to the spec and consistency that keep your rifle running cleanly, with the service life and stability you expect from CMMG.

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