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It is really difficult to PREDICT the differences between one bullet and another of the same construction type when it comes to peak pressure.
There are some experiments with pressure measuring apparatus that show (for rifle cartridges) that max loads (about 60,000 psi) with one bullet can produce pressures on the order of 150,000 psi with what appears to be a similar bullet. Besides bearing surface, there is also the thickness and hardness of the jacket material and the hardness of the core material. Diameter of the bullet with respect to the throat and bore can also make a significant difference in some examples.
In revolvers, it can get even more difficult because of the "rivet" effect when the bullet enters the forcing cone. There it MAY expand radially from pressure on the base and sudden resistance toward the nose, increasing the force needed to force it into the bore/rifling and increasing peak pressure (which occurs at about the same time). A soft bullet that gives less resistance than a hard bullet with mild loads can instead give more resistance under heavy loads. That is why Hornady makes two versions of some bullets in the same caliber and weight. A soft one that is intended for the .45 Colt can cause excessive pressures if loaded to the same data that was developed for a hard one with the .45 Casull or .460 S&W. On the other hand, the hard ones can produce higher (but not usually catastrophic) pressures in the .45 Colt, and of course, they won't expand properly at .45 Colt velocities.
SL1
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