[Ridge Runner]

Larry,
a tapered case under pressure reacts like a wedge, driving it against the bolt face, this is why in those chambers if cut even a tad big like factories do, you see the flattened primers and ejector pin marks. the less taper you have the more likely the case will adhere to a rough chamber and not push as hard against the boltface.
In my Ray Romain built rifle, you see no pressure signs, none, till you lose the pocket.
maybe the guys in the know plan it that way, they build you a rifle you load it up till its insanely fast and your happy, without knowing your pressures.
RR