A gas operating system for a firearm has an energy transmission facility and a gun barrel having a lateral aperture. The energy transmission facility and the lateral aperture have gas communication between them. The gun barrel and the energy transmission facility are mechanically decoupled such that the energy transmission facility does not impede flexing of the gun barrel. All forward forces generated by the energy transmission facility may be transferred from the energy transmission facility to a self-loading facility. The energy transmission facility may include a gas block having a sleeve that is slidably disposed on the gun barrel. The energy transmission facility may include a gas block and a tubular body extending from a receiver to the gas block, one end of the tubular body being slidably received in the gas block. The energy transmission facility may also include the tubular body receiving a gas piston.