You could buy a sling to carry it when you're doing the bulk of your walking. The sling has the added advantage that, when utilized properly, it will significantly improve your marksmanship. Try googling "hasty sling". In addition to utilizing a hasty sling, I suggest that you always try to find a solid object to steady the rifle on, be it an object in the environment, shooting sticks, bipod, etc... I've always found it easier to hold a heavier rifle steady, at least for a time, than a lighter one simply because the heavier rifle has more inertia.
Mike