SIG Sauer have been granted a patent for what they have called an ‘Integral eccentric firearm silencer’. The firearm appears to be based on the popular P320, with an elongated frame and an added silencer/suppressor module. The patent was filed in March 2016, and granted on July 24th.

The suppressor itself has a “removable, disposable and replaceable” wet section, which can be filled with water, oil, gel or grease to help reduce noise. The patent explains that this may take the form of a ‘user-replaceable item’ such as a capsule. This along with the suppressor’s integral expansion chamber would reduce the report of the pistol for the first few rounds. How easily and quickly the wet capsule can be replaced is not discussed. Being a wet suppressor it is likely only the first few rounds fired would benefit from the silencer before the medium in the capsule is exhausted.

Left side partial sectional representation of SIG Sauer’s Integral eccentric firearm silencer (US Patent Office)

The patent’s abstract describes the silencer:

An eccentric firearm silencer includes an elongate body having a projectile entry end, a projectile exit end opposite the projectile entry end, a bore extending through the projectile entry end and the projectile exit end for conducting a projectile there through, and a longitudinal axis X passing through the bore. The elongate body is configured to be coupled, rotatably about or slidably parallel to the longitudinal axis X, to a barrel of the firearm at or near the projectile entry end. The elongate body includes a propellant gas expansion chamber disposed adjacent to, and in fluid communication with, the bore for receiving a propellant gas. The elongate body includes a capsule container mounted eccentrically adjacent to, and in fluid communication with, the propellant gas expansion chamber. The capsule container is configured to receive therein a capsule or ablative cartridge containing an amorphous solid or a liquid.

The patent lists the inventor as Ethan Lessard, while its assignee is SIG Sauer.  Lessard worked for SIG from 2002 until 2016, with five years as a senior designer for the company before leaving to become Vice President of Design at Q, a company he formed with friend, and former owner of Advanced Armament Corporation (AAC), Kevin Brittingham. Lessard has as many as 20 firearms-related patents to his name.

While working along very different lines SIG’s Integral eccentric firearm silencer equipped-pistol might prove a rival for the SilencerCo Maxim9 suppressed pistol. If SIG take the pistol to production the end product may differ significantly, with slide and frame length likely to be variable.

Left side representation of SIG Sauer’s Integral eccentric firearm silencer (US Patent Office)

Check out the full patent here.