Let's say you have unlimited money and acess to all the best tooling and engineers in the world. What do you build first? Here's mine:
Type: Revolver
Caliber: .22 rimfire (interchangeable cylinders for .22 LR and .22 WMR)
Capacity: 12
Action: DA/SA
Cylinder: Swing-out
.22cal Colt M1911, baroque-engraved mother-of-pearl grips, nickel plating, "Once as tragedy" engraved on one side of the slide, "twice as farce" on the other.
Full-on deranged arena shooter brain says "ut2k4 Shock Rifle" though; either that, or the Quake 3 Arena shotgun.