HI GILES. DO 5.5 mm PELLETS GO INTO THE BREECH OF THE BARREL. IF SO I WOULD SUGGEST PULL IT APART AS THE PISTON HEAD WASHERS TEND TO DIS-INTERGRATE OVER TIME AND THE GUN LOSES POWER TO THE POINT THAT IT WILL NOT PUSH OUT A PELLET.
HAS THE RELUM TELLY I SENT YOU ARRIVED YET ? ATB METALMICKEY