YHM, or Yankee Hill Machine, has been a long time (if under the radar) company manufacturing suppressors. They manufacture a bevvy of options, across handguns, rifles, and rimfire. Of particular interest (at least to myself) is their integrally suppressed 10/22 barrel.
At first glance, the barrel is only a 18″ long .920″ bull barrel, but hidden inside the last 8″ or so is a monocore baffle stack. The suppressor is threaded into the barrel via a hex adapter for easy insertion, removal and cleaning.
Unlike other integrally suppressed 10/22 barrels, the YHM does not port the barrel early to reduce pressure and slow supersonic loads to keep them subsonic. As such, its up to the shooter to determine which ammunition to use.
At 18″ with the outside barrel sleeve, having this barrel would make a 10/22 or derivative firearm only a single-stamp gun instead of the common practice of having to SBR a standard receiver and then get a second stamp for the suppressor. While it does remove some versatility from the weapon system, it does work well.
Vigilant Spectre Operations (VSO) got their hands on one courtesy of their relationship with Silencer Shop and put one through its paces on a 10/22 receiver.