Luth-AR BS-10A Buffer Spring .223/5.56 AR-15/M16

The Luth-AR BS-10A is a carbine-length buffer spring built for AR-15 and M16 platforms chambered in .223 Remington / 5.56 NATO. Designed as a direct-fit replacement or upgrade spring for use with an M4-type receiver extension and a collapsible buttstock, the BS-10A keeps your AR running smoothly by providing the correct tension for reliable cycling of the bolt carrier group.

Constructed from 631 stainless steel, the BS-10A offers the corrosion resistance and strength needed for hard-use carbine applications. It is the same spring spec found in Luth-AR's Mil-Spec Carbine Buffer Assembly, making it an ideal standalone replacement when refreshing an existing buffer setup or completing a lower parts kit. Whether you are building a carbine from the ground up, troubleshooting cycling issues, or simply keeping a spare on the bench, this drop-in spring is a core component of any AR-15/M16 carbine buffer system.

Key Features:

• Designed for .223 Remington / 5.56 NATO AR-15/M16 carbines
• Fits M4-type receiver extension with collapsible buttstock
• Made from 631 stainless steel for corrosion resistance and durability
• Drop-in replacement spring; no modifications required
• Part of Luth-AR's Mil-Spec buffer line for AR platforms

Whether you are building, maintaining, or upgrading your AR-15 carbine, the Luth-AR BS-10A buffer spring delivers the consistent, reliable action spring tension that your platform demands.