I'd guess that pressure is related to throat erosion - in fact I'm sure of it. It seems pretty obvious in extreme examples.
I'd suspect that pressure is a vague term embracing both peak pressure and area under the curve and including such things as a secondary peak and other odd observations.
I'd also suspect that pressure in a gas loosely defined is related to temperature - e.g. diesel effect - and so be hard to distinguish. For another complication molecular weight of the gas is a factor - higher velocities with a lighter gas just might act like lower velocities with a heavier gas. Powder gases will vary in chemical composition and so in molecular weight. In fact I think there are many collinear factors with pressure only one of many.
There's a nice military study out of Australia that uses gas velocity at the base of the projectile - which I think might be related to pressure - as one of several factors in predicting erosion.
Some accuracy shooters like an Excel program
Mike�s program predicts barrel life using five variables: 1) Bullet Diameter; 2) Powder Charge weight; 3) Powder Heat Potential (KJ/kg); 4) Pressure (in psi); and 5) Bullet Coating (yes/no). Mike provides a table with Heat Potential ratings for most popular powder types. The user needs to know the pressure of his load. This can be estimated with QuickLOAD.
Mike wrote inter alia "According to Ken Howell, I had to account for pressure." Notice this formula makes no allowance for neck length for what that might be worth.
Add to that
Turbulence is definitely part of it.
Recently I've done some reading of military research into barrel erosion, and the increased throat erosion from cases with shoulders that funnel the gas in front of the neck are well documented. But gas that whirls around in a certain area rather than passing more directly down the bore also tends to increase erosion. In fact, once the surface of a throat starts cracking, erosion speeds up because of increased turbulence due to deflection off cracks perpendicular to the bore.
Given known issues with the 7mm Remington Magnum (and maybe the .243) with respect to variation in pressures as measured in various ballistic labs I'd expect using the 7mm Remington Mag to confound collinear factors more than some other cartridges and so I'd think about using a WSM or something else.
