ORIGINAL: nksmfamjp
I use a top of sight on horizontala lint with vert line coming out of the top. Try making your own sight in taget which is a letter sized paper with a plus shape on it. Lines should be 1~2 in thick. That should help you see the same center point. It is possible to shoot groups under 3" at 100 yards like this.
i did that last year. i actuially posted a while back mentioning that kind of a target......why i didnt try it again i dunno but your right that does work well.