The Magpul ACS (Adaptable Carbine/Storage) Carbine Stock in Mil-Spec, Flat Dark Earth (Magpul part no. MAG370-FDE) is a drop-in replacement buttstock for AR-15/M4 carbines built on mil-spec receiver extension tubes. Magpul packed it with storage: two rear-accessible, water-resistant battery tubes and an integral compartment in the butt keep spares organized without extra pouches. An anti-snag release latch and a supplemental friction lock keep the stock from shifting or catching on gear mid-use, while the 0.30-inch rubber buttpad holds the stock in place on your shoulder even over body armor or a plate carrier. It’s a solid choice for a duty or home-defense carbine that needs dependable storage and a stable cheek weld under real-world conditions.

Key Specifications

• A drop-in replacement buttstock for AR-15/M4 carbines using mil-spec sized receiver extension tubes.
• Two rear-accessible, water-resistant battery storage tubes keep spare batteries dry and within reach.
• An integral storage compartment in the butt of the stock adds a third storage option.
• An anti-snag release latch prevents the stock from accidentally releasing and sliding during use.
• A supplemental friction lock system minimizes stock wobble on the tube for a more stable, accurate cheek weld.
• A 0.30-inch rubber buttpad provides positive shoulder purchase, even over body armor or modular gear.
• Finished in Flat Dark Earth (FDE).

Frequently Asked Questions

What receiver extension does this stock need? It’s a drop-in fit for mil-spec sized AR-15/M4 receiver extension tubes.

Does it have storage for spare parts or batteries? Yes, it has two rear-accessible water-resistant battery tubes plus an integral compartment in the stock butt.

Will it slip on my shoulder with body armor? No. The 0.30-inch rubber buttpad is designed to keep positive shoulder purchase even with body armor or modular gear.

Buy the Magpul ACS Carbine Stock, Mil-Spec, Flat Dark Earth

Order this stock from our Lubbock, Texas gun shop and we’ll have it ready to ship to your door. Shop the full Magpul Industries lineup or browse our complete AR braces and stocks selection.