Aug 4, 2026

US12698946 - Adjustable firearm stock with passive tensioning mechanism

Embodiments of the disclosure relate to adjustable stocks for firearms and methods for installing an independently sprung tensioning mechanism. The adjustable stock comprises a stock body attached to a buffer tube, with a lever-operated tensioning mechanism. The mechanism includes a tensioning block with fins to grip the buffer tube, an indexing pin, and a retaining pin. When the lever is depressed, the tensioning block and indexing pin disengage, allowing longitudinal adjustment of the stock on the buffer tube. The tensioning block applies upward pressure on the tube, compensating for rotational tolerances during assembly. Both the tensioning block and indexing pin move independently when engaging with the buffer tube but move together when disengaging. The indexing pin is biased towards the buffer tube by a spring, while another spring biases the tensioning block. The lever engages the retaining pin to retract both the indexing pin and tensioning block.

Assignee: Magpul Industries Corp.
Inventors: Robert Allan Ross, Timothy Eric Roberts
Filing date: 2024-03-28

firearmstockadjustabletensioning

The patent describes an adjustable firearm stock featuring a passive tensioning mechanism that allows for easy longitudinal adjustment on a buffer tube while compensating for rotational tolerances. The mechanism includes a tensioning block and indexing pin that can be independently engaged and disengaged through a lever-operated system, enhancing the stock’s adaptability and stability.

Claim 1

1 . An adjustable stock assembly for a firearm, comprising: a stock body configured to couple to a buffer tube of the firearm; a tensioning mechanism within the stock body, comprising: a tensioning body configured to couple to the stock body; an indexing pin slidably arranged within an aperture in the tensioning body and having a first spring coupled within the indexing pin; a first retaining pin coupled through a first set of apertures in the indexing pin and coupled through two additional apertures within the tensioning body, and wherein a first end of the first spring abuts to a bottom portion of the first retaining pin; and a second retaining pin coupled through a second set of apertures in the indexing pin, wherein a second end of the first spring abuts to a top portion of the second retaining pin; and a second spring coupled around the indexing pin between the tensioning body and the second retaining pin. a stock body configured to couple to a buffer tube of the firearm; a tensioning mechanism within the stock body, comprising: a tensioning body configured to couple to the stock body; an indexing pin slidably arranged within an aperture in the tensioning body and having a first spring coupled within the indexing pin; a first retaining pin coupled through a first set of apertures in the indexing pin and coupled through two additional apertures within the tensioning body, and wherein a first end of the first spring abuts to a bottom portion of the first retaining pin; and a second retaining pin coupled through a second set of apertures in the indexing pin, wherein a second end of the first spring abuts to a top portion of the second retaining pin; and a second spring coupled around the indexing pin between the tensioning body and the second retaining pin.

Google Patents

https://patents.google.com/patent/US12698946

USPTO PDF

https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/12698946