Dead Air P-Series Piston (M13.5x1 LH)

The P-Series piston is the spring-loaded booster, the Nielsen device, that lets a tilting-barrel pistol cycle reliably with a suppressor mounted. On a Browning-action handgun the added muzzle mass of a can resists the barrel's rearward tilt; the piston decouples that mass during the unlock cycle so the slide still runs. Without it, a direct-thread or fixed mount on a tilting-barrel host short-strokes.

This is the M13.5x1 LH variant, cut for the European 9mm thread pitch found on many European-threaded barrels rather than the domestic 1/2x28. The piston is the part you swap to match the host barrel; the rest of the Dead Air P-Series mount stays the same. It threads into the P-Series pistol mount and works across Dead Air's modular pistol lineup including the Ghost-M, Wolf-9SD, and Wolfman, as well as the P-Series fixed barrel spacer. It is not compatible with the Odessa-9, which uses a different mount.

At $79.79 it is an inexpensive way to add a second thread pitch to a P-Series setup, letting one mount serve both a 1/2x28 host and a European-threaded host by keeping the right piston on hand for each.