NHBuck

I too bought a new slug gun and used lightfields. My scope was not boresighted and it is a Bushnell 1.75x4x32. Your sighting in sounds like my experience carbon copied up until your last slug was off the paper. It took me a total of four or five boxes to zero it 1 inch high at 50 yds dead ctr. At 100 we did not have to touch it at all as it was dead nuts. The reason so many boxes is because I bought 3 different kinds. Federal, Remington coppers and lightfields. I was interested in the grouping first at 25 yds to see which brand fired tightest. Surprising enough if we were to remove the targets we used for each of the three brands from the board we would have seen 2 out of three slugs were in the same hole for each brand. I choose the Lightfields as the cycled smoothest through my 1300. The left overs from the others we just shot down range at blank targets. The following weekend we went back with the lightfields and it took us two boxes to bring it in where we wanted it. Our problem tended to be the mental math in adjusting the clicks to shorter distances. I know it is frustrating but I would definitely bring it back and talk to the shop.