SUBCOURSE MM3676
EDITION A
US ARMY AMMUNITION INSPECTOR MOS 55X SKILL LEVEL 3 COURSE
INSPECTING CONVENTIONAL AMMUNITION PART II
US ARMY ORDNANCE MISSILE AND MUNITIONS CENTER AND SCHOOL
US Army Ammunition Inspector MOS 55X Skill Level 3 Course
INSPECTING CONVENTIONAL AMMUNITION PART II Subcourse MM3676
US Army Ordnance Missile and Munitions Center and School
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This publication is provided for nonresident instruction only. It reflects the current thought of this school and conforms to published Department of the Army doctrine as closely as possible. Users of this publication are encouraged to recommend changes and submit comments for its improvement. Comments should be keyed to the specific page and line of the text to which the change is recommended. Reasons will be provided for each comment to insure understanding and complete evaluation.
* * * IMPORTANT NOTICE * * * THE PASSING SCORE FOR ALL ACCP MATERIAL IS NOW 70% PLEASE DISREGARD ALL REFERENCES TO THE 75% REQUIREMENT
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MM3676 CONTENTS
INTRODUCTION, v Supplementary Requirements, v Credit Hours, v LESSON 1: INSPECTING DEMOLITION MATERIALS, 1 Introduction, 1 M37 and M183 Demolition Charge Assemblies, 2 40-lb. Demolition Cratering Charge, 8 15-lb. Demolition Shaped Charge, 9 Time Blasting Fuse and Detonating Cord, 12 Demolition Firing Devices, 14 Weatherproof Time Blasting Fuse Igniters, 25 Blasting Caps, 29 Practice Exercises, 32
LESSON 2: INSPECTING PROPELLING CHARGES AND THEIR CONTAINERS, 37 Introduction, 37 Inspecting the Propelling Charge Container, 38 Air-Testing Propelling Charge Containers, 40 Inspecting the Propelling Charge, 49 Practice Exercises, 56 SOLUTIONS TO PRACTICE EXERCISES, 65
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MM3676 INTRODUCTION As an ammunition inspector, you will be responsible for inspecting a variety of ammunition items. This subcourse is the second part of a two-part subcourse, Inspecting Conventional Ammunition. It covers the procedures for inspecting demolition materials and artillery ammunition propelling charges and their containers. The two lessons in this subcourse have been adapted from TEC lessons. They support the following tasks from STP 9-55X34-SM-TG: 093-404-3168, Inspect Demolition Materials, and 093-404-3154, Inspect Artillery Ammunition. Supplementary Requirements There are no supplementary requirements in material or personnel for this subcourse. You will need only this book and will work without supervision. Credit Hours Four credit hours will be awarded for the successful completion of this subcourse-a score of at least 70 on the end-of-subcourse examination.
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MM3676 LESSON 1 INSPECTING DEMOLITION MATERIALS
INTRODUCTION In this lesson, you will learn how to inspect the following demolition materials: M37 and M183 demolition charge assemblies, the 40-lb. demolition cratering charge, the 15-lb. demolition shaped charge, time blasting fuse, detonating cord, demolition firing devices, weatherproof time blasting fuse igniters, and blasting caps. During an inspection, you must be able to identify and classify any defects that you find. In an actual inspection, you would record defects and other information on an Ammunition Surveillance Inspection Report (ASIR). Use of the ASIR is covered in another subcourse. Before you begin an inspection of demolition materials, you will use Table 2-2 in SB 742-1 to determine the correct sampling plan. Storage personnel will bring the samples to the inspection area and off-load them. Before they do, you must determine which fire symbol to post. This information is contained in TM 9-1300-206.
Table 2-2. Sample Sizes and Acceptance/Rejection Numbers
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MM3676 M37 and M183 DEMOLITION CHARGE ASSEMBLIES The inspection criteria for M37 and M183 demolition charge assemblies are identical. The M37 demolition charge assembly is made up of the parts shown below. It comes packed in an M85 canvas carrying case. The eight M5A1 demolition block charges are packed in two bags, four charges to each bag. There are two M15 priming assemblies, with two M41 priming adapters per priming assembly.
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MM3676 The M183 demolition charge assembly is made up of the parts shown below. It comes packed in an M85 canvas carrying case. The 16 M112 demolition block charges are packed in two bags, 8 charges to each bag. There are four priming assemblies. They consist of 5 feet of detonating cord with an RDX booster crimped to each end, and a pair of M1 detonating cord clips.
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Inspect outer and inner containers and packaging material, making sure outer containers have proper markings.
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Unpack the demolition block charges and inspect them. The charges are made of composition C4 and are encased in plastic. The M112 charge case has pressure-sensitive tape on its surface to permit quick emplacement of the charge.
Inspect the charges for exudation of an oily or sticky substance. Also look for signs of crumbling. Either defect is MAJOR. If there is any sign of exudation, handle the charge carefully.
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Inspect the plastic covering for cracking disintegration. Both are MAJOR defects.
or
Next, inspect the priming assembly boosters. If you find corrosion, it is a CRITICAL defect.
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A crushed booster is a CRITICAL defect, too.
There is also a CRITICAL defect if the booster is split, cracked, or has an exposed charge.
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40-LB. DEMOLITION CRATERING CHARGE The 40-lb. demolition cratering charge is a metal cylinder containing explosive. A metal ring (lifting/lowering loop) on the top of the container is used to lower the charge into a hole. If this ring is missing, classify it as a MAJOR defect.
Inspect the charge for heavy rust or any penetration that might cause the explosive to absorb moisture. These conditions are MAJOR defects.
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The 40-lb. demolition cratering charge has two priming tunnels located midway between the ends. One tunnel is for the detonating cord, and the other is the cap well. Damage severe enough to prevent these tunnels from carrying out their functions is MAJOR.
15-LB. DEMOLITION SHAPED CHARGE The explosive is in a moistureresistant fiber container. A glass cone is used as a cavity liner. If the glass cone is cracked or broken, the defect is MAJOR.
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Inspect the charge for exudation (oily or sticky substance) or explosive powder leakage. This is a MAJOR defect. Handle the charge carefully.
Inspect for the presence of the tape covering the fuse well. If it is missing, it is a MAJOR defect.
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Examine the cap well insert. If it is loose, it is a MAJOR defect.
Extensive damage to the body of the charge is a MAJOR defect.
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MM3676 TIME BLASTING FUSE AND DETONATING CORD Safety time blasting fuse is orange. M700 time blasting fuse is green with lengthwise measuring bands.
First, inspect to determine if the fuse or detonating cord has become water soaked. If the cord is wet, there is a MAJOR defect.
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Inspect for cuts and gashes. If usable lengths cannot be salvaged from the roll, it is a MAJOR defect. Usable lengths are determined by local SOP. Inspect for excessive cracks in the outer covering. This is a MAJOR defect.
DEMOLITION FIRING DEVICES The M1 delay-type demolition firing device is timed with a glass ampoule containing a corrosive chemical. When the glass is crushed, the chemical eats through the tension wire holding the firing pin, releasing it. For this reason, be very careful not to apply pressure to the copper (ampoule) end of the tube.
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Inspect the markings first. Misleading, incomplete, or unidentifiable markings are a MAJOR defect.
Then inspect for the presence of the safety strip. A missing safety strip is a MAJOR defect. The color of the safety strip shows how long it will take the firing device to function after the ampoule is crushed. The color coding is explained in Table 1-4 of SB 7421375-21. The NSN/DODIC for a firing device, as listed in the DOD Consolidated Ammunition Catalog, will tell you the delay in minutes for the device. By checking the NSN or DODIC against the table in the SB, you can determine what color the safety strip on the firing device should be. For example, a device that should function in 6 to 14 minutes should have a black safety strip. If the safety strip is the wrong color, classify it as a MAJOR defect.
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Inspect for the presence of the protective cup. A missing cup is a MINOR defect. If you cannot remove the protective cup with M2 crimpers or pliers, it is a MAJOR defect.
Examine the threads on the coupling base. If any threads are missing or so damaged that the coupling base cannot be used, classify it a MAJOR defect.
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Fouled threads (dirty or slightly corroded) are a MINOR defect.
Inspect for rust and corrosion. Major rust or corrosion is a MAJOR defect. Minor rust or corrosion is a MINOR defect.
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The M1 or M1A1 pressure-type demolition firing device functions when force is applied to the pressure cap.
First, inspect the markings. Misleading, incomplete, or unidentifiable markings are a MINOR defect.
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Now, inspect for major damage to the firing device, such as a broken firing pin release pin. This is a MAJOR defect.
Inspect for rust or corrosion. Major rust or corrosion is a MAJOR defect. Minor rust or corrosion is a MINOR defect.
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Inspect the coupling base. If it cannot be properly assembled to the firing device, there is a MAJOR defect.
Look for the safety pin and the safety fork. If either is missing, a MAJOR defect exists.
If the safety pin is not adequately secured, classify the defect as MINOR.
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Inspect for the presence of the safety pin cord and the safety fork cord. If either is missing or comes off during your inspection, it is a MINOR defect.
Inspect for the presence of the protector cup. A missing cup is a MINOR defect.
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The M5 release-type demolition firing device has a release plate set with a weight. When the weight is removed, the release plate is sprung and the device fires.
First, inspect the markings. Misleading, incomplete, or unidentifiable markings are a MINOR defect.
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Inspect for the presence of the safety pin. A missing pin is a MAJOR defect. If you cannot remove the safety pin by hand, there is a MAJOR defect. If the cord is missing from either the safety pin or the cotter key, classify the defect MINOR.
Inspect the threads on the coupling base. If the coupling base cannot be properly assembled to the firing device, there is a MAJOR defect.
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Inspect for rust or corrosion. Major rust or corrosion is a MAJOR defect. Minor rust or corrosion is a MINOR defect.
Inspect for the presence of the protector cup. A missing protector cup is a MINOR defect.
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WEATHERPROOF TIME BLASTING FUSE IGNITERS This is the M2 weatherproof time blasting fuse igniter. Inspect the markings first. Misleading, incomplete, or unidentifiable markings are MAJOR defects.
Next, inspect the pull ring. If it is missing or shows evidence of major damage, there is a MAJOR defect.
Look for the paper tube or stopper. If it is missing, classify it as a MAJOR defect.
If any other component is missing or so damaged that the igniter cannot function, it is a MAJOR defect.
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Inspect for rust or corrosion. Major rust or corrosion is a MAJOR defect. Minor rust or corrosion is a MINOR defect.
Inspect the pronged fuse retainer. If any prongs (stakes) are missing or improper to the extent that staked parts are easily separable, this is a MINOR defect.
Inspect the rubber adhesive (plastic sealing compound) around the joint between the stopper and the end of the holder. If it is missing or inadequately spread around the joint between the stopper and the end of the holder, record a MINOR defect.
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MM3676 This is the M60 weatherproof time blasting fuse igniter. unidentifiable markings are a MINOR defect.
Inspect its markings.
Misleading, incomplete, or
If any component needed to make the igniter function is missing or so badly damaged that the igniter cannot be used, there is a MAJOR defect.
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BLASTING CAPS This is an electric blasting cap. Electric blasting caps must be handled with extreme care. Do not drop them or hit them. First, inspect the markings on the box containing the blasting cap. If the markings are misleading as to the strength of the cap, classify the defect as MAJOR. If the markings are unidentifiable as to the strength of the cap, the defect is MINOR.
Next, remove the electric blasting cap from the box and inspect it for splits, cracks, or any other exposure of the charge. Inspect for corrosion. These are all CRITICAL defects.
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Inspect to see that the lead wires are shorted (shunted), either by a shorting tab or by being twisted together. If the lead wires are not shorted, it is a CRITICAL defect. (Be careful. If the lead wires are not shorted, even a small static electric charge can set off the blasting cap.)
Next, inspect the insulation of the lead wires for damage. Lengthwise cracks longer than 1/2 inch, lengthwise cracks ending in a crack running around the wire, and flaking insulation are all MAJOR defects.
Lengthwise cracks of less than 1/2 inch or more than one crack running around the wire, or both these conditions in less than 6 inches of wire, are all MINOR defects.
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This is a nonelectric blasting cap. It should be handled with extreme care. Do not drop it, hit it against a hard surface, or stick anything into it. First, inspect the markings on the box containing the blasting caps. Unidentifiable markings are a MINOR defect. If markings are misleading as to the strength of the caps, it is a MAJOR defect.
Next, inspect the nonelectric blasting cap for splits, cracks, exposed charge, and corrosion. These are all CRITICAL defects.
Finally, inspect the open or flared end of the cap to see if it is bent. If the cap is bent so that proper use is precluded-the fuse will not fit into the cap-it is a MAJOR defect.
When you have completed your inspection, check all necessary forms for completeness and accuracy and send them to the surveillance office. Notify storage personnel to repackage, mark, and return the samples to the storage area. Remove the fire symbols.
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MM3676 PRACTICE EXERCISES 1. What is the defect shown on this M5A demolition block charge? How is it classified?
2. When you are inspecting this priming assembly booster, you find corrosion. How should you classify this defect?
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3. You find heavy rust on the body of the container of the 40-lb. demolition cratering charge that you are inspecting. The rust has not penetrated the case. Classify this defect.
4. The glass cone of this 15-lb. demolition shaped charge is cracked. Classify the defect.
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5. You are inspecting this roll of time blasting fuse. Gashes appear every 7 to 10 inches. Classify the defect.
6. This M1 delay-type demolition firing device is so badly dented that the firing pin may not strike the primer when fired. Classify the defect.
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7. You are inspecting this M1 delay-type demolition firing device. The markings indicate that it should work in 45 to 115 minutes. The safety strip is black. Identify and classify the defect.
8. The safety pin cord is missing from this M1 pressure-type demolition firing device. Classify the defect.
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9. The stopper on this M2 weatherproof time blasting fuse igniter is missing. Classify the defect.
10. The insulation on the lead wires of this electric blasting cap is flaking. Classify the defect.
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MM3676 LESSON 2 INSPECTING PROPELLING CHARGES AND THEIR CONTAINERS INTRODUCTION In this lesson, you will learn how to inspect artillery ammunition propelling charges and their containers. This inspection will include air-testing propelling charge containers. There are many types of propelling charges, but the M4 prop charge is the example used in this lesson. The M4 propelling charge is packed one to a container, which means that 20 containers and 20 propelling charges must be sampled for an inspection (see the table on page 1). For your inspection, choose a time when low humidity is expected. Moisture of any kind can affect the igniter and the propellants of prop charges. If you must inspect prop charges during a period of high humidity, keep their exposure to a minimum. Have the samples transported from the storage area to the inspection area. Make sure the correct fire symbol is posted before storage personnel off-load the samples. The correct fire symbol for prop charges is Fire Symbol 3. In an actual inspection, all defects and other necessary information would be entered on an ASIR.
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MM3676 INSPECTING THE PROPELLING CHARGE CONTAINER
First, inspect the metal container for correct, easy-to-read markings. If markings are missing, illegible, incorrect, or misleading, it is a MINOR defect. Inspect next for inadequate paint coverage, a MINOR defect.
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MM3676 Check for major dents. If a container is damaged to the extent that the propelling charge cannot be removed, it is a MAJOR defect. If a dent impairs the structural integrity of the material or penetrates to expose the charge, it is also a MAJOR defect. In each of these cases, the container must be replaced.
Inspect the container for rust and for pitting and perforations caused by rust. Minor rust that can be removed is a MINOR defect. Otherwise, the classification is MAJOR.
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MM3676 AIR-TESTING PROPELLING CHARGE CONTAINERS Propelling charges will deteriorate or become unserviceable when they get damp. To prevent this, the containers they are stored in are air-tight. These containers are tested periodically to make sure that seals have not deteriorated and caused air leaks. This is called an air test. Failure to pass an air test is a MAJOR defect. To perform air testing, you must first prepare the air test kit for operation. To do this, you will need a source of air, such as an air compressor, capable of providing at least 30 pounds per square inch (PSI) of air pressure. (The air source must provide dry air, so truck air supply tanks cannot be used.)
Follow the procedures and safety requirements of your local SOP. Because of the potential danger from sparks from a fuel-powered air compressor's exhaust, set up the air compressor 500 feet or more from any ammunition storage location or stack of ammunition.
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MM3676 The air test kit consists of two containers that look like suitcases. One container holds the regulator assembly, and the other container holds the air hose and the ground cable. Each kit contains an operator's manual that describes in detail how to set up the kit for operation and to perform the air test. The combined weight of the two containers is 134 pounds. It normally requires two people to carry them. Open the containers and remove their contents. Find a suitable grounding device. One of the best grounds is the ground rod for a storage magazine's lightning protection system. Attach the ground cable of the air test kit to the grounding device. If a grounding device is not available, you will have to drive an approved ground rod into the ground. You must use a ground cable.
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MM3676 Once the ground cable is ready for use and the air test kit is connected to the air source, check the test kit for proper operation. (In an actual test, you would follow the procedures in the operator's manual.) 1. Set the air supply to 30 PSI on the separator gauge. 2. Set output air pressure on the regulator gauge to 3 to 5 PSI. This will prevent too much air pressure from being applied to the container. 3. Pull the trigger on the air gun and allow air to flow through the hose for 3 minutes. 4. Watch the humidity indicator for color change. The humidity indicator must show blue, which indicates dry air.
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MM3676 To perform the air test on a propelling charge container, first ground the container by attaching the ground cable alligator clip to it. Propelling charge containers may be tested without removing them from pallets or storage.
Next, remove the air test plug on the container using a large flat-tip screwdriver.
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MM3676 Then complete the following steps: 1. 2. 3. 4.
Press the adapter on the air gun against the air inlet (where plug was removed). Pull the trigger on the air gun and inject 3 to 5 PSI of air. Release the trigger and keep the air gun pressed against the air inlet. Watch the air gauge on the air gun for 10 seconds.
Any drop in pressure indicates a leaking container, a MAJOR defect. When you find a leaking container, remove the cover of the container and check the rubber gasket for serviceability. Replace the gasket if it is broken or cracked. Then replace the cover on the container and repeat the air test. If the container fails the second test, remove the propelling charge and place it in a serviceable container. Tag the unserviceable container for future identification, inspection, and maintenance.
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MM3676 The humidity indicator on the air test kit must be checked constantly during an air test. If it turns pink, stop testing. Change the desiccant in the desiccant tube and drain the oil and water separator. Allow air to flow through the hose for several minutes. The humidity indicator should return to a blue color and you can continue with testing.
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MM3676 Bleed the oil and water separator every 2 hours during continuous operation to remove the excess water from the test kit.
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After a container has passed the air test, apply a very light coat of graphite grease to the threads on the test plug and replace the plug hand-tight. Then torque the plug to 30 inch-pounds using an inch-pounds torque wrench with a screwdriver bit.
Seal all containers that have been opened with a wire seal.
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MM3676 Continue now with the inspection of the metal container. Open the container by turning the locking bar in a counterclockwise direction.
Remove the container lid and inspect it. If the lid is missing, out of place, deformed, or has a cracked gasket, it is a MAJOR defect.
Remove the prop charge from the metal container and place it on an inspection table.
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MM3676 INSPECTING THE PROPELLING CHARGE
Check to be sure that there are no components missing. A missing component is a MAJOR defect.
Check the prop charge bags to be sure they are without foreign matter. When you find foreign matter, such as mud or dirt, on the prop charge bags, the defect is MAJOR.
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MM3676 Manually inspect the prop charge bags for loss of tensile strength. Visually inspect them for greenish-brown spots. If you find both loss of tensile strength and discoloration, there is a MAJOR defect. If you find the greenish-brown spots but no loss of tensile strength, classify the defect as MINOR.
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MM3676 Inspect the prop charge bags to be sure they have no breaks, tears, or grease. These defects are MAJOR.
Examine the prop charge bags for incomplete stitching-to the extent that the propellant can escape. This is a MAJOR defect.
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MM3676 Inspect the igniter pads for tears, a MAJOR defect.
Inspect the igniter pad for loose stitching, which is also a MAJOR defect.
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MM3676 Manually examine the igniter pad for caked igniter powder, a MAJOR defect. Caked igniter powder is powder that has hardened into a packed mass or contains encrusted lumps.
You are now ready to repackage the prop charge. 53
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Replace the prop charge in the container.
Check to be sure that the gasket (seal) of the container cap is in place.
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MM3676 Insert and twist the end cap into place. Secure the cap by turning the locking bar clockwise until it is hand-tight.
Review all forms for completeness and accuracy and send them to the surveillance office. Notify storage personnel to transport the samples back to the storage location. Have the fire symbol removed from the inspection area. 55
MM3676 PRACTICE EXERCISES 1. This metal container has inadequate paint coverage. Classify the defect.
2. This prop charge container has perforation and pitting caused by rust. Classify the defect.
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MM3676 3. This prop charge container has a dent that does not allow the prop charge to be removed. Classify the defect.
4. The lid of this prop charge container has a deformed gasket. Classify the defect.
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MM3676 5. When you are setting up an air test kit for use with a fuel-powered air compressor, how far from the nearest ammunition storage location must the air compressor be?
6. In the air test of a propelling charge container, how much air pressure is applied to the container? For how long?
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7. This prop charge bag has tears in it that allow the propellant to escape. Classify the defect.
8. This prop charge bag has grease on it. Classify the defect.
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9. You are inspecting this prop charge bag manually and visually and find that it has loss of tensile strength and has greenish-brown spots. Classify the defect.
10. You manually inspect this igniter pad and find caked igniter powder. Classify the defect.
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MM3676 SOLUTIONS TO PRACTICE EXERCISES LESSON 1 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Exhudation, major. See pages 4 and 5. Critical. See pages 4 and 6. Major. See pages 4 and 8. Major. See pages 4 and 9. Major. See pages 13 and 14. Major. See page 13. Safety strip is the wrong color, a major defect. See pages 13 and 15. Minor. See pages 13 and 21. Major. See pages 25 and 26. Major. See pages 26 and 30.
LESSON 2 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Minor. See page 38. Major. See pages 38 and 39. Major. See pages 38 and 39. Major. See pages 38 and 48. 500 feet. See page 40. 3-5 PSI, 10 seconds. See pages 38 and 44. Major. See pages 49 and 51. Major. See pages 49 and 51. Major. See pages 49 and 50. Major. See pages 49 and 53.
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