Normally a steady bench is good enough to sight in rifles and pistols. Especially air pistols and rifles, there is no reason to burn money on the cost of couriering unless you don't really mind. If you are at Sirifort take the pistol etc there and do it. If you want to zero a scoped air rifle then adjust the zero so that your rifle shoots one inch low at ten meters that should let you shoot dead on till 35 m and more.
To ride, to speak up, to shoot straight.