I think last time I did it I put up a 4'X4'sheet of white paper at 50 yards, put a dot in the center aim at it , fire and hope I hit paper, then go from there. Is that about it??
Or can you take the scoped upper and do the look through the bore at bull's-eye, then up through scope to see how far you're off and adjust from there??
"I ain't here for a long time, I'm here for a good time"
King George Straight