I have never been a huge fan of them. But I am thinking about picking up one, maybe the Bushnell Banner series. After my last moose hunt and my scope was knocked off severely, I was thinking if I take a nasty spill in the woods, I could just throw the boresighter on to check zero. My question is how repeatable are they?

So if I zero in my gun at the range with ammo, and then remember the position on the collimator, if I take that thing on and off a few times, should I get the same position on the boresighter? How much will it deviate? One MOA, two , etc? Will the deviation be more elevation or windage?

Does anyone recommend one?