Eightbore, I thought the same until I fired 8 Winchester factory loads after shooting handloads and the AA's varied by maybe 25 fps wherein the handloads were erratic over the same chronograph. It could have been the reloader (me), but I follow the same procedure loading one at a time from start to finish. I may not have had sufficient or consistent seating pressure according to BP, but according to the Ideal manual, seating pressure with modern powders isn't as important as it once was. Gil