The base of a flat bases bullet is not an square as the gauges that Sinclair sells. I have used a bullet and a Sinclair gauge in the same chamber and there is a few thousants difference. The bullet will work as long as you don't let the cases reach max length with the bullet. The difference in my case prep is that I don't set my die to PFL until the cases get snug to bolt closure. I then measure to the datum line and bump the shoulder no more than two thousants. I realize it probably makes no difference which method one choses, just my way of doing things.Rick.
