A valid point and I have not tried racing w/ a rifle, however there
are some very sleak models out there that may work...such as the
Hydrobak a 50oz. model small silhouette, good on a bike, could work w/
a rifle on your back. Or perhaps the good people at camelbak need to
get off their duffs and tap into a new market. it also may require
biathletes to adapt their equipment, all i know is that if you are
hydrating durring a race and your competion isn't all other things
equal it gives you a big edge esp. over long distances