Expo Arms AR-15 Forward Assist Spring - Mil-Spec

Keep your AR-15 forward assist functioning correctly with the Expo Arms Forward Assist Spring — a mil-spec replacement spring that sits behind the forward assist plunger and provides the return tension needed for the plunger to properly engage and disengage the bolt carrier serrations.

The Expo Arms AR-15 Forward Assist Spring is a replacement upper receiver component designed for AR-15 owners and gunsmiths who need to restore correct forward assist function after spring fatigue, breakage, or loss during maintenance.

The forward assist is used to manually push the bolt carrier fully into battery when hand cycling is insufficient — most commonly when running suppressed, in adverse environmental conditions, or when the action has become fouled. The spring behind the forward assist plunger provides two functions: it supplies the return tension that retracts the plunger after each press, and it ensures the plunger properly engages the bolt carrier serrations during the assist stroke without binding or misalignment. A weak or broken forward assist spring causes the plunger to stick, fail to return, or not engage the bolt carrier serrations reliably — compromising the forward assist's utility as an emergency chambering aid. The Expo Arms spring is manufactured to mil-spec dimensions for a direct drop-in fit in standard AR-15 upper receivers. Keeping a spare on hand allows expedient field repair without interrupting operations.

Fits standard AR-15 upper receivers with forward assist assemblies. Mil-spec compatible dimensions. Provides correct plunger return tension and engagement with bolt carrier serrations. Keep on hand for field repair and preventive maintenance.

Manufactured to mil-spec standards for dimensional compatibility and reliable spring tension across standard AR-15 upper receivers. A practical spare for any AR-15 maintenance kit.

An essential spare component for AR-15 owners, gunsmiths, and builders who want to ensure the forward assist functions correctly as an emergency chambering aid under adverse conditions.

Backed by Expo Arms' commitment to quality mil-spec components. Expo Arms manufactures AR-15 parts and accessories to mil-spec standards.