CMMG AR-15 Pistol Grip Star Washer | Anti-Slip, Positive Indexing | For Mil-Spec Lower Receivers | SKU 55CA557 | UPC 810046232156
Lock your pistol grip in place the right way. The CMMG AR-15 Pistol Grip Star Washer provides a secure, repeatable interface between your AR-15 lower receiver and grip, helping prevent loosening under recoil and high round counts. Whether you’re completing a new build, refreshing an older carbine, or swapping to a precision or ergonomic grip, this star-toothed indexing washer is the simple, proven solution for rock-solid grip retention and proper alignment.
Brand: CMMG
Product: AR-15 Pistol Grip Star Washer
Use: Secures pistol grip to lower receiver; improves bite and alignment
SKU: 55CA557
UPC: 810046232156
Why this star washer matters
Positive Bite, Less Back-Out
The star-tooth profile increases surface contact and bite, helping the grip screw hold torque and resist loosening from recoil, vibration, or sling pressure.
Consistent Alignment
A properly seated star washer helps maintain consistent grip angle and safety detent spring alignment, reducing the chances of misalignment during assembly.
Mil-Spec Friendly
Designed around AR-15/M4 mil-spec lowers and common aftermarket grips from leading brands—ideal for duty, range, and competition builds.
Compact, Durable Hardware
Simple, corrosion-resistant construction that stands up to solvents, sweat, and field conditions without deforming.
Low-Cost, High-Value Upgrade
A small part that prevents big headaches—keep a few in your bench kit for future grip swaps and customer builds.
Ideal use cases
New Builds: Ensure your pistol grip installs cleanly with proper tension and alignment from day one.
Grip Upgrades: When changing to a vertical, ergonomic, or rubberized grip, add a fresh star washer for reliable retention.
Armorer & Shop Stock: Inexpensive, essential hardware for high-volume benches and team armories.
Installation (quick guide)
Unload & clear the firearm.
Verify safety detent spring is seated in the grip channel.
Place the star washer on the grip screw (teeth toward the grip).
Align the grip with the receiver boss and insert the screw through the washer into the receiver.
Tighten to snug + 1/8 turn (do not over-torque). Confirm the safety selector functions smoothly and the detent spring is not bound.
Recheck after first range session; retorque if needed.
Pro Tip: A tiny dab of medium-strength threadlocker can be used if your SOP allows—but the star washer often provides sufficient anti-rotation on its own.
Compatibility notes
Platforms: AR-15/M4 lower receivers (mil-spec pattern).
Grips: Works with most AR-15 pistol grips that use the standard central screw and safety detent spring channel.
Screws: Designed for common 1/4-28 or M6 grip screws used by popular grip manufacturers (verify your grip’s hardware).
FAQs
Q: Do I really need a star washer for my grip?
A: It’s not strictly required, but it improves bite and helps prevent loosening—especially on rifles that see heavy use.
Q: Which way do the teeth face?
A: Typically toward the grip so the washer bites the grip’s metal insert or plate as you torque the screw.
Q: Will this work on AR-10/.308 lowers?
A: Most AR-10 lowers use AR-15-style pistol grips and hardware. If your receiver and grip are standard pattern, the washer will work.
Q: Can I reuse an old washer?
A: You can, but for best results use a fresh star washer any time you swap or reinstall a grip.
Key features at a glance
Star-tooth anti-slip design for positive bite
Helps maintain torque and alignment on AR-15 grips
Mil-spec lower and common aftermarket grip compatibility
Corrosion-resistant finish for shop and field use
SKU/UPC: 55CA557 / 810046232156
Technical specs (summary)
Part Type: Pistol grip star washer
Platform: AR-15/M4 (mil-spec pattern)
Function: Anti-slip, improved grip retention and alignment
Material/Finish: Durable, corrosion-resistant hardware
SKU: 55CA557
UPC: 810046232156
SEO highlights (naturally woven)
CMMG AR-15 pistol grip star washer, anti-slip grip washer for mil-spec lower receivers, improves grip screw retention and alignment, easy installation hardware, SKU 55CA557, UPC 810046232156.
Meta for your product page
Meta Title: CMMG AR-15 Pistol Grip Star Washer | Anti-Slip Grip Hardware | 55CA557
Meta Description: Secure your AR-15 grip with the CMMG star washer. Improved bite, consistent alignment, and mil-spec compatibility. SKU 55CA557 — UPC 810046232156.
Small part, big reliability boost—the CMMG AR-15 Pistol Grip Star Washer helps your grip stay tight and properly aligned so your rifle runs the way it should.
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