UTG Pro RBU6BM 6-Position Mil-Spec Stock Assembly

Description

The UTG Pro RBU6BM is a 6-position mil-spec collapsible stock assembly designed for AR-15/M16 platforms. It provides multiple length-of-pull settings to help shooters achieve a consistent cheek weld and ergonomic fit for a range of body types and shooting positions. The kit ships complete with a receiver extension (buffer tube), buffer, action spring, castle nut and end plate to support conversions from fixed stocks or new builds. Components are manufactured to tight tolerances for minimal wobble between the buffer tube and stock.

Key Specifications

• The stock offers 6 positions for adjustable length of pull.
• Compatible with AR-15/M16 (AR-Platform) rifles.
• Includes buffer tube, buffer, action spring, castle nut, and end plate as a complete assembly kit.
• The receiver extension is made from aircraft aluminum with rolled threads and hard anodizing.
• The buttstock is a polymer stock made from impact-resistant high-strength material.
• The assembly is identified as Model 4 in manufacturer data.
• The finish is specified as mil-spec.
• The product weight is listed as 18.2 oz.
• The kit is described as Made in the USA by the manufacturer.
• The package dimensions are listed as 2.10 x 5.60 x 9.10 inches.

This UTG Pro RBU6BM stock assembly is built as a practical, no-nonsense upgrade or replacement for AR-15/M16 builds and conversions. Its combination of a machined receiver extension and impact-resistant polymer stock delivers dependable fitment and a range of user-adjustable positions to suit different shooters and applications. If you need a complete mil-spec style carbine stock kit that includes the tube and hardware, this assembly provides the core components required for installation and reliable operation.