This advocate is rocking a Pneu-Dart X-Caliber (Gen 1) gauged projector with a timber camo finish, sometimes referred to as a darting rifle. It has a 29″ barrel.
The device has been superseded by the Gen 2 X-Caliber projector, which features a 39″ barrel for greater range and improved accuracy. Refer to this Pneu-Dart video.
Western Horse Watchers Association 