Midwest Industries MISTAPSF Buffer Tube with Side Folding Adapter - Black 4140 Steel

The Midwest Industries MISTAPSF is a heavy-duty side-folding adapter paired with an integrated Mil-Spec buffer tube, purpose-built to give AR-pattern pistol platforms a compact, swing-away rear mounting solution without giving up strength. It is machined from 4140 steel and finished in a rugged black manganese phosphate coating for long-term wear and corrosion resistance.

The folding mechanism uses a full-length locking lug for maximum strength and delivers a solid, positive lock-up in both open and folded positions with no play under recoil. Deployed, the adapter adds 2.5 inches to the overall length of the host firearm; folded, it adds only 0.75 inches for the shortest possible carry profile. The complete assembly weighs in at just 8.4 oz, so it adds meaningful function without bogging down the rear of the receiver.

The included tube accepts any Mil-Spec carbine stock, pistol stabilizing brace, or compatible accessory, making the MISTAPSF a versatile drop-in upgrade for AR-15 pattern pistol builds. Per the manufacturer, this adapter is intended for use on pistols only and is not a stock - pairing it with an approved pistol stabilizing brace keeps the host legally classified as a pistol while giving the shooter a shouldered platform when needed.

Proudly made in the USA by Midwest Industries, a respected American manufacturer of tactical rifle accessories, the MISTAPSF delivers the fit, finish, and lock-up that demanding shooters expect from a premium side-folder.