Short range group benchrest matches allow time for barrel cleaning and reloading between matches, minimum, by the rules, 30 minutes. The more relays there are, the more time you will have. Typically, a match is 7 minutes long, and for a given class of rifle, and distance there are five matches. For a match where there are two rifle classes, this results in a total of 20 matches over the course of a two day event. The overall winner is not the person who shot the smallest group, but rather the person who shot the smallest average of all groups. The competitions are so competitive that staying in sharp tune as conditions change through the day, and event, is mandatory. This often involves adjusting loads as temperature changes. If you are interested in the mechanics of how this is managed at a match PM me and we can concentrate on that. Here is a video showing how one of the top French shooters does it.