Brand new all-metal semi automatic Co2 BB air rifle is branded Huntex (AKA Huntsman / Hell Boy etc.) - different brands, but manufactured by the same Chinese maker). The fully detachable magazine comprises both an 18 BBs feeding tube and a Co2 bulb. This M4 is the REAL dimentions of 5.56mm M4 and can take a real M9 bayonet and real M4 magazine with INERT ammo, effectively turning this rifle into a de-activated replica, which can be used for training. It has all the correct markings of a real rifle including a 3-position fire selector, 5.56mm calibre and serial number. The Co2 M4A1 imitates the high quality alluminium-made upper and lower receivers of a real weapon, with a steel gas tube and all moving parts including a charging handle, forward assist button and removable carry handle. What's more, we have increase the power of the magazine by about 15% - 20% by re-machining its main air valve to allow more air preasure into the barrel as an option. Spare magazines with increased energy of appx 4 Joules (estimated 450 fps) are available