i dont rifle hunt much these days, but i immediately thought if i were in that situation id sight the rifle in, and use a bore sight afterwards to check where you laser is. they're never dead accurate so you may even have to mark which way is up on the boresight so you can be sure its relatively close. also for bore sights i highly recommend you go to a truck stop and get a small piece of reflective tape, or "conspicuity tape" and carry a few inches with you. this makes the laser really bright so you can actually see it in the daylight. just a suggestion, might be better than shooting off a rifle near where you target might be.
