4.5.6 Paint adhesion. The method of test shall be as prescribed by
TT-C-490. The test shall be made on the painted bourrelet of each unit
of the sample forward of the rotating band. Visible exposure of under-
lying phosphate coating or ferrous metal of any unit of the sample, as a
result of the test, shall be recorded as a defect.
4.5.7 Corrosion resistance. The method of test shall be as prescribed in
American Society for Testing and Materials (ASTM), ASTM B117. The paint
shall not be disturbed, however, the rotating band and unpainted surfaces
of the sample projectiles may be masked out by a wax coating or other
suitable material. The salt spray solution and exposure time shall be as
specified in 3.6.3.
4.5.8 Metal parts security. The method of test will be as prescribed by
DARCOM-R 715-505, Volume 8, as applicable. The test sample will be assembled
to comply with requirements of Dwg. D7259191, Cartridge, 20mm, for M55 Type,
Target Practice, projectile metal parts test. The test cartridges, at
ambient temperature, will be fired in bursts of 50 shots in an M39 gun.
The gun barrel will be at ambient temperature for the firing of each burst.
The cyclic rate of fire will be recorded for informational purposes.
5.1 Packaging and packing, level C. Each lot of projectiles shall be
packed as specified by Dwg. F7258861 or Dwg. D7259136.
5.2 Marking, level C. Marking or labeling of packed cartons or containers
shall comply with applicable requirements of MIL-STD-1169.
6.1 Intended use. These projectiles are intended for use with the M103
type cartridge case in the assembly of target practice cartridges.
6.2 Ordering data. procurement documents should specify the following:
6.2.1 Title, number, and date of this specification.
6.2.2 Projectile model and type.
6.2.3 Place of inspection, if not place of manufacture.
6.2.4 First article sample requirements.
(see 3.3, 4.3 and 6.3)
6.2.5 Packaging, packing and marking instructions.
(see 5.1 and 5.2)
6.2.6 Provision for shipment and testing of first article and production
lot samples for metal parts security. (see 4.5.8)