Firearm with forward gas vent passage

A barrel assembly for a firearm comprising:

• an elongated barrel body defining a bore and having an exterior;
• the elongated barrel defining a barrel port at an intermediate portion of the elongated barrel and communicating between the bore and the exterior;
• a gas block defining a barrel passage configured to closely receive the intermediate portion of the elongated barrel;
• the gas block defining a block port registered with the barrel port and interfacing the block port at a port interface;
• the gas block including an action facility communicating with the block port;
• a gas vent passage defined between the elongated barrel and the gas block;
• and
• the gas vent passage communicating from the port interface to an exterior location.

A firearm upper receiver comprising:

• an upper receiver frame;
• an elongated barrel connected to the frame;
• the elongated barrel defining a bore and having an exterior;
• the elongated barrel defining a barrel port at an intermediate portion of the elongated barrel and communicating between the bore and the exterior;
• a gas block defining a barrel passage configured to closely receive the intermediate portion of the elongated barrel;
• the gas block defining a block port registered with the barrel port and interfacing the block port at a port interface;
• the gas block including an action facility communicating with the block port;
• a gas vent passage defined between the elongated barrel and the gas block;
• and
• the gas vent passage communicating from the port interface to an exterior location.