81MM MORTAR

Ace your homework & exams now with Quizwiz!

Cause Of A Misfire

1) Defective ignition cartridge. (2) Defective, damaged, or loose firing pin. (3) Fouled firing pin or firing pin obstructed by extraneous material. (4) Fouled bore. (5) Excess oil or water in the bore. (6) Misaligned stabilizing fin assembly. (7) Foreign matter or excess paint on round

Five Steps Of Crew Drill

Bisect Rough Level Level Elevation Level Cross-level Traverse Half The Distances To The Post And Level Cross-level

Cause Of A Cook-Off

(1) Exceeding the maximum rate of fire. (2) Smoldering debris in the barrel.

Cause Of A Hangfire

(1) Improper storage and handling of the ammunition. (2) Fouled bore. (3) Fouled ammunition

M252 81mm Mortar

M252 refers to the entire 81mm mortar system assembled.

Fire Commands

Mortar To Follow Shell And Fuze Mortar To Fire Method Of Fire Deflection Charge Time Setting Elevation

SMALL DEFLECTION/ELEVATION CHANGE

When the gunner is given a fire command from the FDC, the gunner must determine if the deflection setting is less than 60 mils, and the elevation setting less than 100 mils from the current data that is on the sight. If the new deflection is within 60 mils and the elevation is within 100 mils, it is a small deflection/elevation change

LARGE DEFLECTION/ELEVATION CHANGES

When the gunner is given a fire command from the FDC, the gunner must determine if the deflection setting is more than 60 mils, and/or the elevation setting more than 100 mils from the current data that is on the sight. If the new deflection is outside 60 mils and/or the elevation is outside 100 mils, it is a large deflection/elevation change

Gun Crew Members

Squad Leader Gunner Assistant Gunner First Ammunition Bearer Second Ammunition Bearer/Driver

CHARACTERSITICS

The M252 81mm mortar and the M224A1 60mm mortar share very similar characteristics. The 81-mm mortar is a smooth-bore, muzzle-loaded, drop fired, high-angle-of-fire weapon. The components of the mortar consist of a cannon, mount, base plate and the sight unit.

M3A1 Baseplate

The baseplate is of one-piece construction, and supports and aligns the mortar for firing

Bipod

The bipod provides front support for the barrel and carries the gears necessary to lay the mortar

Cannon M253

The cannon assembly consists of the barrel that is sealed at the lower end with a removable breech plug, which houses a removable firing pin. At the muzzle end is a cone-shaped Blast Attenuator Device (BAD) that is fitted to reduce noise. The BAD is removed only by qualified maintenance personnel.

Weights

The complete mortar system weighs 93 lbs. The cannon weighs 35 lbs, the bipod weighs 27 lbs, and the M3A1 baseplate weighs 29 lbs and the M64A1 sightunit weighs 2.25.

Elevating Mechanism

The elevating shaft is contained in the elevating leg; to the left of the elevating leg is the elevating hand wheel

Ranges

The maximum range for M889 ammunition in the conventional mode is 5,608 meters. The minimum range for M889 ammunition is 83 meters.

M177 Mount

The mount consists of elevating and traversing mechanisms and a bipod.

Rates Of Fire

The rapid rate for the 81mm mortar is 30 rounds for the first 2 minutes. The sustained rate of fire is 15 rounds per minute indefinitely.

Traversing Mechanism

The sight bracket is attached to the buffer carrier, which is fitted to the traversing screw assembly

M64A1 Sight Unit

This unit provides self-illuminating sighting capability for indirect fire in the conventional mode. deflection and elevation


Related study sets

Lección 9: Recapitulación y Flash cultura

View Set

Understanding Questions DALL-E 2

View Set

CHA: blood labs, Sickle Cell, Anemia

View Set

Licensure Practice Exam Questions Part 2

View Set

Ch.13: Introduction: Understanding Psychological Disorders

View Set

Principals of management final vt

View Set