INTERPRETATION OF M3 BORESCOPE VIEWS.

ARMY

TM 9-6650-235-13&P

MARINE CORPS

TM-08552A-13&P

k. On later configurations, install the 115-V

electrical power cable assembly and place the 115-V/24-

V toggle switch (23) in the 115-V or 24-V position as

required.

l. The 24-V slave cord assembly or the 24-V

battery cord assembly may be used to obtain 24 volts

from vehicle for inspecting bore of weapon.

m. Insert the M3 Borescope (24) into cannon bore

(25). Adjust eyepiece assembly (26) until a clear focus is

achieved and lock in place. As the bore is examined,

turn the M3 Borescope clockwise or counterclockwise to

get complete coverage. After a complete revolution of

the M3 Borescope, move it about 1 inch (or more as

desired) and repeat the examination.

2-7. INTERPRETATION OF M3 BORESCOPE VIEWS.

The bore of the weapon as seen through the M3

Borescope is usually not life-size. Due to the various size

bores to be inspected and the design of the M3

Borescope, the magnification of the viewed area varies.

magnification to be encountered in each weapon.

2-8.

RECORDING RESULTS OF M3 BORESCOPE

INSPECTION.

NOTE

The reference line that runs within 4.0

inches of the length of the extension

tubes

is always alined with the

mirror of the illuminating head

assembly.

The M3 Borescope inspection should be conducted

according to the guidance given in TM 9-1000-202-14,

Evaluation of Cannon Tubes. Results of the inspection

should be recorded by expressing the deficiency in

o'clock position and distance from the end of the cannon

tube, using the scale and reference line on the side of

the M3 Borescope.

2-15