The penalty for missing a single target can only be the time it takes to re-load and use one of the 3 spare rounds. That can take around 15 seconds, so it can be worth taking a risk and shooting quicker to get the targets down faster. Also the time can be made up on the tracks so it is worth skiing a bit faster and coming in to shoot with a higher pulse rate and risking more misses. Each team may have it's own tactics but as the race changes the tactics can change. If a team needs to quick shoot to be in contention for a medal they may take a risk and ski and shoot faster to give themselves a chance.
Of course there is also the pressure of going head to head with other athletes and the difference between gold and nothing can be missing a target by a millimetre and letting the whole team down. If you are German or Russian that pressure can be like taking a penalty at the cup final.
Edited: 20/02/2013 at 12:28