The VP9 "Veterinary Pistol" (um...yeah) from Brugger & Thomet is a manually operated 9x19mm handgun with a quite effective suppressor built right onto the barrel. It is, in fact, a remarkably close copy of the British SOE Welrod pistol from World War II, right down to some pretty minor details.

The action uses a two-lug rotating bolt, which is unlocked and cycled by hand between shots. The magazine doubles as the grip, making for a compact and concealable package that would not necessarily be an obvious gun to the typical observer. The suppressor uses 4 rubber wipes which the bullet must actually make its own holes in - this makes it quieter than a typical suppressor, but only until the wipes have substantial holes shot through them (10 rounds or so). At that point the noise of each shot is still much quieter than a unsuppressed pistol, but not as quiet as when using new wipes. This is not a gun intended for a high volume of fire. That said, the suppressor body is easily removed, and the wipes are easily replaced.