Caliber: 7.29 cm

Over-all length: 11.09 inches.

Over-all weight: 6.00 lbs.

Nature of the fuze: Nose percussion.

Material: Steel.

Over-all length: 4.22 inches.

Maximum diameter: 2.85 inches.

Diameter at nose: 0.81 inch.

Wall thickness: Varies from 0.23 inch aft to 0.12 inch forward.

Weight of filling: 0.62 lbs.

Over-all length: 6.34 inches.

Over-all Diameter: 2.60 inches.

Wall thickness: 0.10 inch.

Over-all Diameter: 2.86 inches.

Over-all height: 1.29 inches.

Number of Venturi: 14; A. 7 offset (outer circle); B. 7 straight (inner circle).

DESCRIPTION. This is a spin-stabilized projectile of conventional design, consisting of a warhead and a rocket motor. The projectile is essentially the same as the 7.3-cm propa-gandagranate 41, except that a warhead provided with a percussion fuze and self-des-troying delay has replaced the leaflet container. (See fig. 205.)

The projectile is fired from the Föhn Gerät, a 35-frame launcher with fast elevating and transverse gears. The launcher is capable of firing 35 rockets simultaneously.

The self-destroying feature of the rocket plus the characteristics of the launcher sug-gest that the projectile is intended for use against low flying air-craft in the form of bar-rage fire.

Warhead. The warhead is ogival in shape and open at the rear where it is threaded in-ternally to receive the rocket motor. The explosive filling is a performed charge of 280 grams of RDX/TNT/wax pressed in a block and wrapped in wax paper.

The warhead is doubly fuzed, being fitted with a nose percussion fuze and a self-des-troying base fuze. The RAZ 51 is screwed directly into the nose of the warhead. In the base of the charge is a cavity which accommodates the self-destroying delay, located in a tube screwed into a metal plug in the forward end of the motor. The delay consists of a quick-fire igniter, initiated by the motor ignition charge, and what appears to be a tra-cer composition. When the tracer composition burns out, it flashers through an orifice into a primer-detonator which detonates the main charge.

Rocket Motor. The rocket motor consists of a plane cylindrical body and a cup-shaped base plate. The body is screwed into the warhead at the forward end into the flange of the base plate at the rear. The forward end of the rocket motor has a flange below which is located a metal closing plate which separates the warhead from the propellant compartment and also holds the rear end of the self-destroying assembly for the explosi-ve charge. Below this plate is a stamped metal supporting ring containing the ignition charge for the propellant.

The base plate, which screws on the rear end of the body, has seven outer off-set venturi, seven straight venturi, and central drilling for a percussion primer.

The propellant charge consists of a single cylindrical stick with a central perforation and eight outer perforations. Raised ribs around the circumference of the propellant serve to keep it clear of the motor body and permit external burning. Two 1/8-inch blocks of pow-der, cemented to the base of the charge, act as spacers and keep the venturi free from obstruction.

The charge is ignited by the flash from the percussion primer. The flash is transmitted along a celluloid tube in the central drilling to the ignition charge at the forward end of the propellant. The celluloid tube is of conventional design. It contains a quickmatch train and is closed at each end by a cylindrical block of gunpowder.

Figure 205 – 7.3-cm R. Sprgr. Rocket