MIL-STD-1258(WC)
30 June 1972
4. GENERAL REQUIREMENTS
4.1
The standard comparison gage (fig. 1) established In this
standard
is in the form of a photograph depicting the acceptable
interior
surface of 5.56mm, 7.62mm and Cal .30 barrels after chromium
plating,
high pressure proof firing and cleaning.
4.1.1 The other photographs contained herein (fig. 2 thru 20)
show examples of unacceptable interior surface conditions. These are
provided only as an aid in identifying the type of defect which caused
rejection of the barrel during normal visual inspection (see 5.1) so
that appropriate corrective action may be taken. These photographs do
not establish and are not intended to be used as borderline acceptance
standards for workmanship type defects.
4.2 Visual examination of the barrel for workmanship type defects
should be accomplished without the aid of optical instruments. Barrels
rejected by normal visual inspection may be examined with a borescope to
determine the nature and severity of the unidentified defects and the
corrective action to be taken.
4.3 Appearance of chromium deposits. The chromium deposit shall
be smooth and homogeneous and shall be free from visible defects such
as unplated areas, blisters, nodules, pits, flaking, peeling and cracks.
A dull or milky appearing deposit shall not be cause for rejection.
"Burnt" and "frosty" deposits are unacceptable.
4.4 Appearance of the chromium plated surface. The chromium
plated surface shall be free from visible machining defects such as drill,
`namer, and broach marks, tears and gouges exceeding the surface finish
requirements of applicable detail drawings. Visible evidence of copper
deposits after proof firing that prevent or interfere with conduct of
normal visual inspection shall be cause for rejection.
4.5 The application of the visual camparison standards to acceptance
inspection of the interior surfaces of 5.56mm, 7.62mm, and Cal .30 barrels,
is contained in Section 5 herein.
4
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business