Cobra Billet Trigger Guard Install on an AR-15

By Texas Precision Optics Inc | Published: 2026-11-01

Category: How-to Guides

Swap your AR-15 trigger guard for the blue Cobra billet aluminum model. Follow the step-by-step install, including the roll pin and a fit check on Anderson lowers.

Quick answer

The Cobra billet aluminum trigger guard installs on mil-spec AR-15 lower receivers using the supplied M6 hex screw, but it will not fit Anderson mil-spec lowers without modification. Check your lower's brand and roll pin setup before you start.

Why the Cobra guard is more than a color change

The Cobra guard is machined from aircraft-grade aluminum, so it replaces the standard polymer or cast guard with a rigid part that also adds a fang-shaped magazine reload assist and a rest for your trigger finger. That combination matters if you run fast reloads or want a consistent index point outside the trigger guard. The trade-off is weight and fit: the guard is lightweight, but it is still metal, and the product notes specifically exclude Anderson mil-spec lowers without modification.

When to skip this upgrade

If your lower is an Anderson mil-spec receiver, plan on modification before the guard will seat correctly. If you want a drop-in part with no fitting, a standard mil-spec guard is the safer choice. Also skip the Cobra if you prefer a polymer guard for weight savings or if your lower uses a proprietary trigger guard design rather than the standard roll-pin interface.

Step-by-step Cobra trigger guard install

Verify lower compatibility: Check the roll mark on your lower. If it is an Anderson mil-spec receiver, stop and plan the required modification before continuing. A five-second brand check prevents a stalled install.
Unload and separate the upper: Remove the magazine, clear the chamber, and separate the upper from the lower so the trigger guard area is fully accessible. Never work on the trigger group with a loaded lower.
Remove the old trigger guard: Drive out the existing roll pin with a roll pin punch, then lift the old guard free. Support the lower so the pin holes are not stressed. Use a punch that matches the pin diameter to avoid wallowing the hole.
Test-fit the Cobra guard: Set the Cobra guard in place and check that the screw hole aligns with the lower and that the fang does not contact the magazine well. If the hole does not align on an Anderson lower, stop before forcing the screw.
Secure the guard with the M6 screw: Thread the supplied M6 hex screw through the guard into the lower and tighten until the guard is snug, then verify the trigger and magazine release still move freely. Snug, not overtightened, keeps the aluminum guard and lower threads intact.
Function-check and reassemble: Reattach the upper, confirm the trigger resets and the safety engages, then run a few dummy rounds through the magazine well to check the reload assist. A final function check catches any interference before range time.

Product facts

AR-15 Cobra Billet Aluminum Trigger Guard Blue: Fits mil-spec AR-15 lower receivers and includes an M6 hex screw, but will not fit Anderson mil-spec lowers without modification. Confirm your lower's brand before ordering so you know whether the guard is a direct install or needs fitting.
AR-15 Cobra Billet Aluminum Trigger Guard Blue