Honestly for what you are describing why spend a pile of money on a pack to haul some shells and calls around.
I used one of these in elementary school for several years hauling homework and a trapper keeper. Don't need a special spendy pack to haul a little bit of gear around.
http://m.eastbay.com/index.cfm?uri=product&model=62774&sku=501-008&SID=7726&inceptor=1&cm_mmc=SEM-_-PLA-_-Google-_-501%2D008&gclid=CKa25KSvyNECFcdhfgodmEoAFQ
