Dreyse Needle Gun - Ammunition and Mechanism

Ammunition and Mechanism

The cartridge used with this rifle consisted of the paper case, the bullet, the percussion cap and the black powder charge. The 15.4 mm (0.61 in) bullet was shaped like an acorn, with the broader end forming a point, and the primer attached to its base. The bullet was glued in a paper case known as a sabot. Between this inner lining and the outer case was the powder charge, consisting of 4.8 g (74 grains) of black powder.

The upper end of the paper case is rolled up and tied. Upon release of the trigger, the point of the needle pierces the rear of the cartridge, passes through the powder and hits the primer fixed to the base of the bullet. Thus the burn-front in the black powder charge passes from the front to the rear. This front-to-rear burn pattern minimizes the effect seen in rear-igniting cartridges where a proportion of the powder at the front of the charge is forced down and out of the barrel to burn wastefully in the air as muzzle flash. It also ensures that the whole charge burns under the highest possible pressure, theoretically, minimising unburnt residues. Consequently a smaller charge can be used to obtain the same velocity as a rear-ignited charge of the same bullet calibre and weight. It also increases the handling security of the cartridge, since it is virtually impossible to set the primer off accidentally.

The Dreyse rifle was an example of a caseless ammunition rifle in the sense that it was designed so that the soldier had to load the rifle, but not expel the fired case. The case was in fact made from paper (as were many of the first cartridges), so it burnt entirely when the round was fired. The second innovation that made the Dreyse effectively a caseless ammunition rifle was that the primer was physically connected to the bullet, so it left the rifle together with it.

There was also a blank cartridge developed for the needle-gun. It was shorter and lighter than the live round, since it lacked the projectile, but was otherwise similar in construction and powder load.