Roscoe,
I found out about the sling changin' the point of impact in the most embarrisin' way. I was visitin' my Dad after about a 7 year absense, he took me pasture griz huntin' with his new Mossberg Chuckster. I carried the rifle and he carried the glasses. As hog huntin' goes he spotted one when we were in the middle of a hay field, and it was in the adjoinin' one. It was about a 150 yard shot so I sat down and got into the sling. He said "You can't shoot from out here lets get up ti the fence and rest the rifle". Now I'd only been huntin' Caribou twice and elk 4 times since the last time I saw him. Not to mention speed goats and mulies in open country. To make a long story short I fired about 5 times and he kept sayin' "Low". Finally I emptied the clip, and we walked over to the chuck which humped up on the second shot. It was pretty sick so he stomped it's head and threw in into the hole. Then he took me to his rest, where I shot a 1.5 group at 100 yards. Then I got into the sling, and shot three shots into an even nicer inch, but all about 6 inches low. []