Pellet loading expls

In ProgrRept July-Sept 1949 are given photographs of luminosity curves for deton of PETN of loading d 1.40 in air as recorded on a sweep trace of 10 20 microsec duration In ProgrRept Apr-June 1950 is given the following table of relative luminosity of "detonation peak for three expls in pellet form ... 

The second effect of ram movement usually works in the opposite direction (slower ram speeds plus a dwell at the peak press may cause, an increase in density). This effect is due to the fact that, at loading pressures usually used, expls are stressed beyond their yield points and creep or flow plastically. This effect, of course, becomes more important at vary high pressures, such as those used for delays. In addition to increasing the density, slower speeds plus dwell of the ram result in a more uniform density 4) Pelletizing... 

Most powdered expls that are to be pressed are prepressed into pellets. The die of the loading tool permits closer tolerances and better finishes than are reasonable for cases that are loaded by direct pressing. Exceptions are primer mixes, PETN, and LA, although LA is pelleted in Canada on a production basis... 

Although pellets for exptl use are loaded by single operation methods in which weighed charges are pressed either by stop loading or by controlled pressure techniques, quantity production of pellets is accomplished in automatic pelleting machinery, in which the explosive is metered volumetrically by the controlled movements of punches. Single stroke presses of the types used for expls produce about 90 pellets per minute while rotary presses have rates of about 700 pellets per minute... 

Frequently, when it is desirable to attain the close confinement and continuity characteristic of expls loaded directly into their cases, it is difficult or inconvenient to do so. In such instances, pellets are inserted into the cavities and reconsolidated by pressing. In designing for reconsolidation, consideration must be given to the tolerances and variations of hole dimensions, pellet weight, and pressure-density relationship that enter into the determination of the relative location of the surface thru which the reconsolidation pressure is applied. Where this dimension is critical, the reconsolidation is done to a stop so that the tolerances appear in the density of the reconsolidated pellet. 

At the present time (1981) there is one expl that uses wax as the vehicle. This compn, covered by Specification MIL-C-60051, consists of 86/14 RDX/wax (Ref 89). It is loaded by a puddling technique in combination with pellets of Compn A-3, and is used as the main charge of a 165mm high capacity projectile... 

Compressibility of Explosives The compressibility of a solid explosive is a measure of the change in vol caused by the application of pressure. Compressibility is the relationship between the density and the pressure applied to a granular or powdered expl. The resulting curve is useful where the loading of ammunition or of pellets is done by compression... 

Method A. A 20 g charge of expl is cast or pressed in a copper cylinder of %11 ID and / 11 wall. The loaded tube is placed vertically on a 4" square piece of cold-rolled steel plate, / thick, supported by a short length of heavy steel tubing, placed in a vertical position. The expl charge is boostered by a 5 g pellet of tetryl which in turn is initiated by a No 8 detonator(Refs 1,3 4)... 

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