Name: Luth-AR Mil-Spec 6-Position Carbine Buffer Tube Black - BS-15M
Brand: Luth-AR
SKU: BS-15M
Price: 24.9 USD
Availability: InStock

Luth-AR Mil-Spec 6-Position Carbine Buffer Tube Black - BS-15M

$24.90

No reviews yet Write a Review

Product Description

Luth AR Mil Spec Buffer Tube Buffer Tube Fits AR 15 Mil Spec Dia Black BS 15M UPC 859819007133

Product Description

The Luth-AR® 6-Position Mil-Spec Carbine Buffer Tube in Matte Black (SKU: BS-15M / UPC: 859819007133) is an essential, precision-machined lower receiver extension engineered for reliable cycling, structural durability, and repeatable stock staging on AR-15, M4, and AR-10 carbines. Founded by legendary precision stock designer Randy Luth, Luth-AR manufactures components held to rigid dimensional standards, making the BS-15M an ideal replacement tube for worn factory receiver extensions or the foundational backbone of a ground-up tactical carbine build.

Precision-extruded and CNC-machined from certified aircraft-grade 6061-T6 aluminum, the BS-15M provides exceptional tensile strength, impact rigidity, and thread-shear resistance under continuous recoil impulses. The exterior and internal bore are treated with a MIL-A-8625 Type III Class 2 Hardcoat Anodized matte black finish that delivers a scratch-resistant barrier against field abrasions, chemical bore solvents, rain, and corrosive sweat. The interior bore is micro-finished to reduce spring drag, minimize cyclic twang, and promote smooth, uninterrupted cycling of standard and heavy carbine buffers.

Engineered to true Mil-Spec dimensional tolerances (1.148" outer diameter), the tube features 6 precision-cut length-of-pull (LOP) adjustment detent positions, allowing shooters to quickly tailor their buttstock extension to heavy tactical gear, plate carriers, or varying shooting stances. With standard 1.185"-16 UN-2A receiver threading and a reinforced forward lip that secures the buffer retainer pin without binding, the BS-15M ensures a solid, rock-steady interface with all Mil-Spec collapsible buttstocks, including the Luth-AR MBA-3 and MBA-4 modular stocks.

*Armorer Bench Notes & Real-World Staging Guidance:*

Fitment Matrix: Direct fit for all standard mil-spec forged and billet AR-15, M4, M16, and AR-10 / LR-308 lower receivers. Features true Mil-Spec outer diameter (1.148" OD); will NOT properly fit Commercial-Spec buttstocks (1.168" ID). Accepts all standard 3.25" AR-15 carbine buffers and standard carbine buffer springs. AR-10 / .308 note: Fully compatible with large-frame AR-10/LR-308 carbine setups when paired strictly with a short 2.5" .308 carbine buffer and .308 carbine spring. Torque specs: Thread castle nut and end plate on, torque castle nut to 38–40 ft-lbs using an armorer's castle nut wrench, and stake the end plate into the castle nut notch with a center punch.

Ensure the host firearm is completely clear, magazine removed, and chamber visually and physically verified empty.

Thread a standard mil-spec castle nut (locking notches facing the rear) and receiver end plate onto the external threads of the BS-15M.

Depress the lower receiver buffer retainer and spring, and thread the buffer tube clockwise into the receiver tower until the forward lip captures the buffer retainer shoulder without binding its vertical stroke.

Align the receiver end plate into the lower receiver's alignment notch, hand-tighten the castle nut forward against the plate, and verify that the bottom 6-position adjustment rib is aligned precisely vertical at 6 o'clock.

Torque the castle nut using a calibrated armorer wrench to 38–40 ft-lbs, stake the end plate firmly into the castle nut staking notch with a center punch, and install your buffer spring and buffer.

Key Features

True Mil-Spec Outer Diameter (1.148" OD): Compatible with all standard Mil-Spec collapsible buttstocks (Luth-AR, Magpul, B5, BCM).
Aircraft-Grade 6061-T6 Aluminum: Precision-extruded and CNC-machined for superior tensile yield strength and lightweight durability.
6-Position Length-of-Pull Adjustment: Granular stock adjustment intervals provide custom eye relief and plate carrier clearance.
MIL-A-8625 Type III Hardcoat Anodize: Deep military-grade matte black finish protects against scratching, oxidation, and solvents.
Smooth Low-Friction Interior Bore: Eliminates cycling drag, suppresses spring resonance, and prevents premature buffer wear.
Precision 1.185"-16 UN-2A Threads: Cut to clean mil-spec tolerances for perfect alignment into forged and billet lower receiver towers.
Rear Evacuation Vent: Bottom rear drainage hole allows rapid moisture and debris venting in adverse outdoor field conditions.
Broad Caliber Compatibility: Ideal for 5.56 NATO, .223 Rem, 300 BLK, 6.5 Grendel, 9mm PCC, and .308 Win (with 2.5" buffer).
Designed by Industry Pioneers: Engineered under the quality oversight of Randy Luth, founder of DPMS and Luth-AR.