9.2.1 Pistols used in competitions under NSRA rules must conform with one of the following:
9.2.1.1 any pistol (single shot, semi-automatic or revolver) chambered for the 5.6 mm (.22 in) rimfire cartridge,
barrel length including the cylinder, not exceeding 254 mm (10 in); sights may be adjustable but not over
254 mm (10 in) apart. The trigger must support 1 kg (2.2 lb) weight; or
9.2.1.2 any type of compressed air or CO2 pistol calibre not exceeding 5.6 mm (.22 in) and of dimensions not
exceeding those in Rule 9.2.1.1. The trigger must support 500 g (1.1 lb) weight