How Do You Define "Obviously"?
There is a saying in science that fact is the greatest enemy of theory. While there is a significant share of the firearm-purchasing market that will spend money on the basis of theory (particularly if that theory supports a prior opinion), others prefer some some of record of real-life performance in the choice of life-saving equipment.
Many decades ago, W.E. Faribairn and E.A. Sykes published a little book, Shooting To Live with the One-hand Gun. Aside from the continuum of point shooting they present, based on their observations of 666 actual gunfights, one of the more intriguing chapters deals with "stopping power." Essentially, they state that they had initially expected the best results from large, slow-moving, soft lead bullets. In fact, they saw very inconsistent results, with a few surprising successes with small-caliber, high-velocity jacketed bullets fired from Mauser pistols. However, in the ensuing decades there has not been any significant body of experience demonstrating that a small-caliber, high-velocity handgun bullet, hollowpoint or otherwise, performs better than a medium- or large-caliber hollowpoint, albeit at lower velocity.
We get the most documentation of bullet preformance from officer-involved shootings. With street-proven performance from many medium- and large-caliber rounds, it's unlikely that police agencies will volunteer their officers as guinea pigs with smaller calibers. While Ruger has just introduced the ".327 Magnum" as a defensive cartridge, I doubt that it will produce enough real-life data to substantiate the claim that a small-caliber, high-velocity handgun round is "obviously" a good handgun round for self-defense. Barring such a body of knowledge, I find it hard to believe that it would be finacially worthwhile to develop modern pistols in chamberings such as the the 7.62x25mm.
