wow, from a 5" barrel. I do NOT agree that a bullet should frag into small pieces at impact, but if that bullet was an alumium hp, with a large, conical base like the THV-Arcanes (5" 9mm, 45 grs, brass bullets, 2400 fps) then you would really have something! Even in a 4" barrel, you'd for sure still have 2400 fps with the 9x23, and probably close to that with the 357 Sig, or a 9x19, rechambered to take the longer, stronger case of the 356 TSW. Real power, in ccw pistols. Problem is, such a hp would penetrate Kevlar vests, so it's unlikely to ever be sold to the regular public. It would not be illegal, per se. the federal anti AP law only prescribes bullets made of steel, cast iron, beryllium copper, bronze, or brass. Zinc, tin, aluminum, and other copper alloys are not mentioned, therefore they are legal, and HAVE been used to make hg bullets in the past.