US Cartridge, 20mm HE, HEI, Mk 3 Mod 1 - 64
The explosive filling of the HE projectile is press loaded in three equal increments. The HE-I projectile is similarly loaded, but the first increment consists of an incendiary mixture, the other two of HE, either tetryl or pentolite.
This round is also issued B.L. & P., with an inert filler and a dummy nose cap.
The many modification numbers are to distinguish between products from different contracts.
Nothing else to see.
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