A projectile launcher having an upper receiver capable of swinging away from a lower receiver is disclosed. In one aspect, the lower receiver having a first end and a second end contains a firing control chamber. While the second end is located closer to barrel of the launcher, the first end of launcher is located closer to a buttstock. The firing control chamber includes a gas channel, wherein one end of gas channel is coupled to a valve and another end of gas channel reaches to the top of external wall of the chamber. The upper receiver having a first end and a second end contains a bolt chamber. The second end of upper receiver and the second end of lower receiver are pivotally coupled whereby allowing the first end of upper receiver to be pivotally swung away from the first end of lower receiver.