Chap,
I'm using an apurature (spelling?) front sight in the Lyman 17. The hole looks to be about 6 to 8 inches at 100 yards. I think of it as putting a circle around the vitals and shoot. At 75 yards the 2" dot is just visible for me, I use it as a center point and place the inner and outer circles of the front sight and the peep sight all concentric to each other with the spot as the center. Seems to be working so far.