The German Recoilless Gun, versions of which are described on pages 110 and 119, operates without a recoil or counterrecoil mechanism. This is made possible by a design which allows the propelling gases to escape to the rear when the weapon is fired. This unusual design of brass coated steel cartridge case, which makes possible an unexpectedly long range for such a weapon, is provided with a primer in its side and a plastic base insert. This plastic base insert, 1.12 inch thick, momentarily withstands the pressure of the ignited propellant and then disintegrates, being blown out the rear of the weapon along with the released propellant gases.
The propelling charge and igniter are made up to suit side ignition. The propellant is contained in a cylindrical bag; the igniter bag is in the form of a cap, and fits over the end of the propellant bag. The igniter composition is contained in pockets formed between the outer fabric and the lining by quilting the bag. There are twelve pockets around the side and six in the end. The propellant is a flashless composition of the normal “Gudol” type and the igniter composition is the normal porous chopped cord.
SPECIFICATIONS
| Propellant weight | 6.9 lbs. | |
| Propellant analysis | ||
| Nitrocellulose (N-12.34%) | 34.47% | |
| Nitroguanidine | 33.81% | |
| Diethylene Glycol dinitrate | 30.22% | |
| Graphite | 0.14% | |
| Potassium Sulphate | 1.36% | |
| Propellant bag | Viscose rayon | |
| Cartridge case | Brass coated, 1010 type steel | |
| Thickness of brass coating | 0.0001 in. | |
| Base insert | Phenol-formaldehyde resin |
German: p. 313