I am looking for a men's small backpack for a 12 year old boy. Hate to buy new as fast as they grow. We packed his sleeping bag and pad in a 38 liter I have and there is not much room. He is about 5' 2" and I tried to measure the torso as Osprey suggests and it is around 16.5". I am looking for a traditional overnight preferably light pack not a hunting specific pack. Thanks