It's situational. I find most hiking packs to be a little too small to carry all my hiking gear. So if I'm going car camping I like to bring my Hunters Element boundary pack 35L just packing rations, ammo and water also somewhere to put my jumper if it gets to hot. It works pretty well, comfortable pack.
If I'm hiking into a spot and then shooting I bring my hiking pack and use the drink bottle pocket as a place to hold my stock and slip the barrel up through the tensioning straps, the only downside is once my camp is set up my hiking pack is too big to bring with me while I'm out stalking so I bring a bumbag with me for rations, water and extra ammo