Figure 1. Location of Fort Lewis
model C7, but is manufactured to the same specification as the U.S. M67. The
current British hand grenade is the Model L2, which is based on the older U.S.
M26 hand grenade.
The M67 and C7 grenades contain 186 g of Composition B as the main
charge. Composition B is composed of 60 percent military grade RDX and 39
percent military grade TNT. Military grade RDX generally contains HMX as a
major impurity with concentrations of HMX ranging from 8 to 12 percent (U.S.
Army 1984). Military grade TNT is about 99 percent 2,4,6TNT with the
remainder made up of other isomers of TNT, the various isomers of dinitroto-
luene (2,4DNT being the most abundant), 1,3-dinitrobenzene, and 1,3,5-
trinitrobenzene (TNB) (Leggett, Jenkins, and Murrmann 1977; George et al.
1999). Thus, each grenade contains about 100.4 g of RDX, 11.2 g of HMX, and
71.8 g of TNT in the main charge. The detonator in the M67 also contains 1.3 g
of RDX; thus, each grenade contains a total of about 101.7 g of RDX, 11.2 g of
HMX, 72.5 g of 2,4,6TNT, with less than a gram of 2,4DNT, TNB, and other
impurities. The M26 grenade contains about 84.2 g of RDX, 9.4 g of HMX,
60.1 g of TNT, and 0.6 g of 2,4DNT and other impurities.
The soil in the grenade impact area is coarse gravelly sand with stones as
large as 15 cm (Table 1). Grass sparsely covers areas not recently affected by
range use. The four impact areas are consecutively numbered, and judging from
the numbers of craters in each, have been used to a similar extent. Range 3,
which was selected for extensive soil sampling, is approximately 11 m wide at
the launch end (Figure 2). The sidewalls that enclose the impact area widen to