Perforated grains proplnts

British, German, Italian, Russian and Japanese proplnts examined at Picatinny Arsenal during WWII included squares, perforated discs, single-perforated tubes, single perforated grains, multi-perforated grains, spheres and strips. The basic idea behind the use of the varied forms is connected with the desire for a propint with a... 

As to the web thickness, the larger the value, the slower is the proplnt. For single -perforated grains, as most US small arms proplnts are, the web thickness is equal to half the difference betw the outside diam(such as 0.049") and the diam of the perforation such as 0.015")... 

Note Accdg to L.Shulman ofPicArsn, this app can be used only for "nonperforated grains (such as used in rockets). It cannot be used for "perforated grains (such as used in cannon proplnts). This is because the flame would go down the perforations and... 

Multi perforated Propellant Grains. See Cannon Propellant or Cannon Powder in Vol 2, C30—31, Grains of Smokeless Proplnts in Vol 6, G123... 

Type 99 20-mm Ammo (p 440) existed as Mk I and Mk II and was copied from the Swiss Oerlikon design. The proplnt consisted of graphited single-base, single-perforated cylindrical grains, 13.6g for Mk I and 21.4g for Mk II. Both Mk s used the same types of projectiles, which were as follows ... 

Two 30-mm Aircraft Cannons, the Type 2 and Type 5 were used during WWII. They were of Swiss (Oerlikon Co) design. Same proplnt was used in ammo of these guns. It consisted of graphited, single-perforated cylinderical grains of NC. The projectiles used were as follows 30-mm Type 5 HE Proj was filled with cast Pentolite (p 451)... 

This means that if a proplnt burning in a closed vessel is without perforations(such as cordite), there is no erosion of the grains, but if a proplnt is perforated(as in US single- and multiperforated grains) there is erosion in channels but not on the outside surfaces of grains... 

It has been found that there are several methods to stabilize the burning in central perforations of rocket proplnts. The most common method is the drilling of radial holes through the grain web at even intervals along the axis, as described in detail in Ref 3,pp 124-7. Another method of stabilization is insertion of a rod of nonburning material in the center of the axial perforation of the grain(Ref 3,p 128). A third... 

The main shapes of such proplnts are cord, slotted tube grains with a 7-hole perforation. Other forms which have been employed for special purposes are flake, ribbon, scroll disc. The cord form is the simplest type to manuf to control dimensionally, but has the disadvantage that... 

Cordite ]P 76. This is a solventles6 proplnt consisting of NC(12.2% N) 49-6, NG 41.4 Carbamite 9.0%. It was prepd in the form of grains 1-.7 in diam, 1.0 long diam of perforation 0.6" (Refs 23 35). Its decompn during accelerated aging was investigated chromato-... 

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