inner tens is only used for tie-breaking. The changing of these traditional targets is handled by each shooter, by means of electronic – or more archaically, manually operated – carrier devices. In major competitions, only one shot may be fired on each target, a number that can increase to two, five or even ten with lowering level and importance of the competition. Used targets are collected by range officials to be scored in a separate office. During the last few decades, these paper targets have been gradually replaced by electronic target systems, immediately displaying the results on monitors. When using these systems, actual scoring lines are not printed, but the location of the impact hole (which can be determined acoustically) is automatically converted into corresponding scores by a computer. ISSF rules now require the use of these systems in top-level competitions. They are generally used in other international competitions as well, and in some countries they are even common in national competitions. Equipment To promote comfortable and accurate shooting from a standing position match air pistols must have fast lock times, shoot practically recoilless and vibration-free and exhibit minimal movement and balance shifts during discharge. The pistol must also be able to be tailored by adjustable user interfaces and various accessories to individual shooters personal preferences. Combined with appropriate match pellets the pistol has to produce a consistent 10 ring performance, so a non maximal result during the initial phase can be attributed to the participant. The pistols used are gas-driven with a caliber of 4.5 mm (.177 in). The minimum trigger pull weight is 500 gram (17.6 oz), half that of a sport pistol, and the grip restrictions are similar to sport pistols, but the box in which an air pistol must fit is larger: 42 by 20 by 5 cm (17 by 8 by 2 in). This allows for longer sight lines and also gives room for cocking arms, although with a few exceptions (such as the Baikal IZH-46M) modern match air pistols use pre-filled air, or less commonly carbon dioxide, containers. The maximum overall weight is . The pistol must be operated by only one hand from a standing position, and may only be loaded with one pellet at a time. For the 10 metre air pistol and air rifle disciplines match diabolo pellets are used. These pellets have wadcutter heads, meaning the front is (nearly) flat,