You are in luck today. The absolute best handgun money can buy would be the Foonblotz Derpinatrix Bitesatbothends in .477 CCE. It's a little long for a pistol, technically, with its 8.234 inch barrel, which is just barely long enough to take advantage of about fifty percent of the .477 CCE cartridge, which is really designed for a 16.5 inch carbine barrel at the very least
But, some masochistic individuals feel that taking a rifle cartridge like the .477 CCE and putting it into a handgun platform gives them the same firepower as the rifle. This is only partially true, as the slower-burning rifle powder doesn't have quite as much time to push the projectile with a shorter barrel. However, the .477 CCE still gets some respectable velocity out of the Derpinatrix Bitesatbothends, and with the angled side-feed magazine, it is more comfortable to grip than a Desert Eagle, with about three times the power.
The action is of the innovative four-stroke piston type, which allows the expanding gases of the powerful .477 CCE cartridge to smoothly cycle the action despite the significantly high pressure of the round.
Sights are of the partridge blade with buckhorn v-notch type, more commonly seen on lever-action semi-automatics, but for a cartridge of this type in a handgun, it is more than appropriate.
Magazines generally hold four rounds for the civilian version. The military version includes a twin-strut magazine well reinforcement allowing the use of the longer ten round magazine. As a side note, the twin struts are just the right distance apart to be used as a bottle opener, which apparently makes them popular with front-line troops to which these aweseome pistols are issued.
As you may well guess, they are not standard military issue, but only special issue to Delta Force Seal Rangers for special tactical operations.
The military version also includes mounting hardware for night vision apparatus, affixed firmly to the opposite side of the pistol utilizing highly innovative 268800 FPF (Furlongs Per Fortnight) Single-Sided Bonding Strips.
The only downside to issuing these amazing sidearms is their cost, which is offset only by the volume in which a government contract usually runs, making the military version roughly half the cost of the civilian version. Since it is a pistol, with the civilian version being incapable of utilizing the military-capacity magazines, it is not considered an NFA firearm nor is it regulated in any way other than a Title 1 firearm.
Civilian cost at last check was 12,500 dollars. Although it has been some time since I knew anyone who might have had one, and I personally have only seen the military version in person. Due to the failure of my lobotomy, however, I was not allowed to actually fire one.
On the upside, the military HOLSTERS do work with the civilian models, but for some reason only come in white Arctic Camouflage.
I suspect Big Pookie's in Moosephart, MT, the only known civilian outlet for the Foonblotz Derpinatrix Bitesatbothends may have some custom leather rebuilt out of old shoes and sold at a handsome profit. You should probably inquire there if you desire to carry such a powerful military firearm.
You won't find much in the way of specifications in the public domain, however, due to the hush-hush nature of the SpecOps community.
But these pistols do exist.
Trust me.
And if it's good enough for the Delta Force Seal Rangers, it's good enough for me.