The Firearm Blog

I recently wrote about the new Boberg XR9 pistol which features the magazine beneath the chamber. Dr. StrangeGun discovered that the Gabbett-Fairfax Mars pistol was the first pistol to feature this configuration.

High tech and ugly (Photo from Horst Held)

From wikipedia:

The Mars Automatic Pistol was a semi-automatic pistol developed in 1900 by the Englishman Hugh Gabbet-Fairfax. It was manufactured by Webley & Scott and distributed by the Mars Automatic Pistol Syndicate. The Mars Automatic Pistol is famous for being available in a variety of 8.5 mm, 9 mm and .45 calibres. These were all bottle shaped cartridges with a heavy powder loading, making the .45 version the most powerful handgun in the world for a time. It used a unique long recoil rotating bolt action which ejected spent cartridges straight to the rear.

The Mars Automatic Pistol was rejected by the British War Office as a possible replacement for the Webley & Scott Revolver, then in service with the British Army, because of the unacceptable large recoil, muzzle-flash, and mechanical complexity. It has since become a collectors item because of its rarity and as an example of the earliest developments in semi-automatic pistols.

I dug up the pistols’ patent. The patent drawings show how the rear ward feeding works.

Although the pistol was not practical back in 1900 it was an ingenious design.

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)!

What a beautiful looking pistol

Standard black frame, Gen II prototype

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.

The video:

Specs:

Caliber: 9mm
Length: 5.8”
Height: 4.2”
Width: 0.95”
Weight: 19.5 oz with magazine
Barrel Length: 4.2”
Capacity: 7+1
Action: Rotating-Barrel Locked-Breech
Sights: Dovetail windage, 5.1” radius
Trigger Pull: 6.5 lb DAO
Safeties: 3

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.