<P> The relay teams consist of four biathletes, who each ski 7.5 kilometres (4.7 mi) (men) or 6 kilometres (3.7 mi) (women), each leg skied over three laps, with two shooting rounds; one prone, one standing . For every round of five targets there are eight bullets available, though the last three can only be single - loaded manually one at a time from spare round holders or bullets deposited by the competitor into trays or onto the mat at the firing line . If after eight bullets there are still misses, one 150 m (490 ft) penalty loop must be taken for each missed target remaining . The first - leg participants start all at the same time, and as in cross-country skiing relays, every athlete of a team must touch the team's next - leg participant to perform a valid changeover . On the first shooting stage of the first leg, the participant must shoot in the lane corresponding to their bib number (Bib #10 shoots at lane #10 regardless of position in race), then for the remainder of the relay, the relay team shoots on a first - come, first - served basis (arrive at the range in fifth place, shoot at lane 5). </P> <P> The most recent addition to the number of biathlon competition variants, the mixed relay is similar to the ordinary relay but the teams are composed of two women and two men . Legs 1 and 2 are done by the women, legs 3 and 4 by the men . The women's legs are 6 kilometres (3.7 mi) and men's legs are 7.5 kilometres (4.7 mi) as in ordinary relay competitions . </P> <P> In 2014, single mixed relay was introduced by the IBU . Each team has a man and a woman, and each runs two 3.0 kilometres (1.9 mi) legs, except the last leg where the man completes 4.5 kilometres (2.8 mi) for a total 13.5 kilometres (8.4 mi). </P> <P> This event was first held at the Biathlon World Championships 2005 in Khanty - Mansiysk, and it was added to the 2014 Winter Olympics . </P>

What kind of rifles do they use in the olympics