Hey All, just recently purchased a rem 870 express 12ga. with smooth and slug barrel w cantelever scope mount. Wound up going with a nikon slug hunter scope. So to get to the point I was at the range sighting the scope in with no problems, fastest sight in think I ever had. So I knew something had to happen so sure enough as I was leaving a guy stopped me and told me to re check my zero on the scope after swapping barrels back and forth, bc he was off 2' when he put his slug barell back on from the smooth. Since I wanted to go hunting with that gun that afternoon, I didn't test that theory. My question to y'all is, is this true? Have any of you had this same experience? As always I Appreciate all your feed back. Thanks.