Section 2: Equipment

Calibre: 4.5 mm (.177 cal) only (ISSF Section 7); Maximum weight: 5.5 kg (12.1 lb) including all accessories; Power source: Pre-charged pneumatic (PCP) or spring-piston; CO2 and gas-powered rifles are prohibited (ISSF Section 7)

Source: Section 7, Section 8, Section 9, Section 6

Send this to your friend — argument over.