What about the projectile itself? Delta may be shooting something other than ball from their pistols, but this probably would not carry over to all of today�s Army. Modern LEO loads with their law enforcement hollow points may not fit the bill either. But what about the new generation of expanding fmj projectiles. They are not hollow points and kind of act like a wall anchor to implode upon itself to increase in diameter on the terminal end. If this were something considered in the mix, then suddenly the 9mm comes back into play. You would then maintain the lower recoil, the magazine capacity, in addition to the harder-hitting.
Well here's the problem with that. The expanding FMJ's expand on IMPACT pressure vs. hydraulic pressure like the JHP. The advantage that the JHP has is when it hits a solid object, it doesn't expand, so barrier penetration isn't affected. But when it hits a fluid object, like living tissue, the fluid pressure gets inside that cavity and rips the bullet open.
So the expanding FMJ would certainly get you the greater stopping power, but you'd completely give up barrier penetration, and in military and LE roles, barrier penetration is VERY important.
What's more, while The Hague convention does somewhat specify FMJ, you don't get a pass just because your bullet starts out as an FMJ, they specifically forbade any expanding bullet... ("bullets which expand or flatten easily in the human body")
