Yes it will, I agree with you 100% that it will change the tuning too. Look at rimfire target shooters with their barrel tuners. I have found though at least on my sample of 2 that it didn't change my groups by any better or worse than I can shoot.Anything that changes the mass of your barrel is going to change the tuning of your loads. Assuming that something hanging off the end of the barrel is only going to change the point of aim and not affect the tuning is something you can't count on at all. Any accuracy testing should only be done the way you're going to be hunting.