Magpul UBR Gen 2

The Magpul UBR Gen 2 Collapsible Stock features a unique design with a custom receiver extension (buffer tube) that accommodates carbine buffers, springs, and aftermarket A5 buffer systems. At 18.8 ounces for the stock and about 21.3 ounces installed with the receiver extension, it's nearly five ounces lighter than the original UBR while retaining legendary durability. The stock provides eight adjustment positions with 3.5 inches of length of pull range and a fixed cheek piece for consistent cheek weld at any position.

The UBR Gen 2 includes the required custom receiver extension tube and buffer spacer, but requires a separate carbine buffer and spring (M4, SR-25, or A5 length). This custom buffer system design adds complexity and weight compared to standard stocks. The robust construction was designed for demanding applications where durability outweighs mobility concerns, but at more than 21 ounces installed, it's significantly heavier than tactical stocks.

For most users, the UBR Gen 2's weight and complexity don't justify the benefits over simpler, lighter alternatives. A CTR or B5 SOPMOD provides excellent performance at 8-11 ounces, saving 10-13 ounces for equivalent functionality. The UBR Gen 2 is best reserved for builds where maximum durability is paramount and weight is irrelevant, or for shooters who specifically want the custom buffer system design.