AR-15 Trigger Spring

AR-15 Trigger Spring

This United Defense trigger spring is a replacement part for the fire control group of an AR-15 lower receiver. The fire control group is the trigger, hammer and disconnector that work together to fire the rifle. The spring pushes the trigger forward again after each shot so it can reset. Keep one on hand if you build lowers, rebuild a worn trigger group, or want a spare in the parts box before a small spring goes missing during cleaning.

Features

• Double-Torsion Design — One length of wire is wound into two matching coils, one for each side of the trigger, so the tension stays balanced across the part.
• Looped Center Bridge — A closed, squared-off loop joins the two coils and bears against the underside of the trigger to drive it forward.
• Bent Leg Tips — Each of the two long legs ends in a short angled bend that helps it stay seated on the hammer pin.
• Bare Metal Finish — The wire is bright and uncoated, as the photographs show, with no paint or plating to flake off inside the receiver.
• AR-15 Lower Receiver Fit — The spring is shaped for the trigger group of an AR-15 pattern lower.
• Direct Replacement Part — It swaps in for a worn, bent or lost trigger spring without changing any other component.
• United Defense Manufacture — This is a commercial part made by United Defense, not military surplus.

Fit And Installation

The two coils slide over the trigger on either side, with the center loop under the trigger and the legs pointing forward. When the trigger goes into the lower and the pins are in place, the bent leg tips rest on top of the hammer pin. Fitting it means pulling the trigger pin, so it is easiest to do during a lower build or a full trigger group service. Run a function check afterward to confirm the trigger resets cleanly.