The XR9 is a prototype 9mm pocket pistol by Boberg Engineering. What makes it special is that the magazine located directly under the chamber. This allows it to have a full size barrel (4.2”). Think of it as a bullpup equivalent in a pistol (not the best analogy but you get the idea)!
The Boberg feed mechanism differs from traditional feed mechanisms in that it draws the cartridge backward from the magazine (see video).
What is not obvious from this view or the video is the rendundancy of the mechanism. The lifting device, consisting of the lifting linkage and the ramp, imparts a kinematically balanced motion to the cartridge as it is lifted. This is important because the cartridge is accelerated rearward an upwards of 2000 g’s. Any impact on the cartridge by the ramp is absorbed by the resiliency of the ramp. This combination, along with containment of the case flange, is sufficient to feed cartridges; however, a top stop is added to prevent any further upward motion of the cartridge.
Even a poorly designed lift mechanism would feed cartridges somewhat reliably when using the top stop alone; however, the Boberg XR9 uses both kinematic balance and the top stop to provide complete and redundant control over the cartridge as it is picked from the magazine, lifted to be in-line with the barrel, and placed into the chamber.
Weight: 19.5 oz with magazine
Barrel Length: 4.2”
Action: Rotating-Barrel Locked-Breech
Sights: Dovetail windage, 5.1” radius
Trigger Pull: 6.5 lb DAO
It will be very interesting to see what becomes of this pistol.
More info here.
Hat Tip: Ahab
UPDATE: The pistol is expected in 2009.