Yes a member of OFS can be a hunter. In the original rule for the OFS there was a prohibition against caring arms, due to the feudal wars at the time. This was removed in subsequent rules for the OFS. HOWEVER, the Franciscans are very much into care for animals and the environment so hunting for just sport would be highly discouraged. If you are hunting for yourself/family, hunting legally, fairly for the game and eating the entire catch it would be allowed. Francis never promoted vegetarianism so he recognized people had to hunt/fish to get food. Of course for his early Order since they were into begging for food and couldn’t bear arms others would have to be the hunters/fishers.
However your feelings towards this may change after becoming a member.