Examination of Ammunition

Question 1

How do you examine ammunition that is all of the same type and in good condition ?

Answer 1

• It may only be necessary to test fire one or two cartridges. This can be done using the firearm it was submitted with (if present) or using a reference firearm
• or large numbers of cartridges a representative sample quantity can be fired. The size of this sample quantity depends on the quantity of the ammunition and its condition.

Question 2

How do you examine ammunition that is in bad condition?

Answer 2

There could be a risk of a cartridge case rupturing; in such cases either none should be test fired, or the ammunition shall be test fired remotely.

Question 3

How do you examine ammunition that is home made?

Answer 3

1) be disassembled;
2) some of the propellant burned (to test for viability); and
3) the primer discharged (either in a reference firearm or with a bench mounted primer firing device).

Question 4

How should results from home made examination be dealt with?

Answer 4

The results of these tests shall be recorded. The disassembly of ammunition containing projectiles with potentially dangerous substances such as tracer material, incendiary material or explosives should not be undertaken.

Question 5

Examination of bullets shall include the recording of:

Answer 5

• Calibre
• mass;
• diameter;
• rifling direction and number of lands and grooves
• bullet style;
• bullet type;

Question 6

What are class characteristics in firearms?

Answer 6

Measurable features of a specimen that indicate a restricted group source.

Question 7

What are class characteristics of Bullets?

Answer 7

• Calibre (Bullet Diameter)
• Number of Lands and grooves
• Direction of twist
• Widths of land and groove impressions

Question 8

What is the calibre of a bulet?

Answer 8

In ammunition caliber is a numerical term, without the decimal point, included in a cartridge name to indicate the nominal bullet diameter

Question 9

In ammunition the lack of decimal point in the decimal indicates?

Answer 9

Without the decimal point, included in a cartridge name to indicate the nominal bullet diameter.

Question 10

How may the widths of lands and grooves impression aid in identification?

Answer 10

If a firearm is not submitted, these measurements of LIMP and GIMP can be used in determining the general rifling characteristics (GRC) of the firearm involved.

Question 11

When measuring the LIMPS and GIMPS what is important?

Answer 11

that the reference points used for beginning and ending a measurement, and the positioning of the land or groove conform with a standardized, discipline-wide practice

Question 12

What is the nose of the bullet?

Answer 12

The point or tip of the bullet.

Question 13

What is the ogive of the bullet?

Answer 13

The curved portion of a bullet from that portion of the body which engages the barrel rifling (bearing surface) and or bullet nose.

Question 14

What is the Bearing Surface of the bullet?

Answer 14

That portion of a bullet’s outer surface that comes into direct contact with the interior surface of the barrel.

Question 15

What is the Cannelure of the bullet?

Answer 15

A circumferential groove generally of a knurled or plain appearance on a bullet or cartridge case.

Question 16

What is the use of the cannelure?

Answer 16

Three uses include crimping, lubrication and identification.

Question 17

What is the base part of the bullet?

Answer 17

The rear or base portion of a bullet

Question 18

What is a hollow point bullet?

Answer 18

A bullet with a cavity in the nose to facilitate expansion.

Question 19

What is a full metal jacket (FMJ)

Answer 19

A projectile in which the bullet jacket encloses the entire bullet, with the usual exception of the base.

Question 20

What is a total metal jacket?

Answer 20

A bullet whose core is completely encased with copper jacketing or by a thick copper plating.

Question 21

What is a jacketed soft point (JSP)?

Answer 21

A projectile designed with exposed lead at the nose of a jacketed bullet, to initiate expansion of the projectile upon impact.

Question 22

What is a wadcutter bullet?

Answer 22

A cylindrical bullet design having a sharp shouldered nose intended to cut target paper cleanly to facilitate easy and accurate scoring.

Question 23

What is a semi wadcutter (SWC)?

Answer 23

A projectile with a distinct, short truncated cone at the forward end.

Question 24

What is a turncated cone?

Answer 24

A projectile with a distinct, short truncated cone at the forward end.

Question 25

What is a boattail?

Answer 25

A specific design of bullet having a tapered or a truncated conical base.

Question 26

What is a round nose bullet?

Answer 26

An elongated projectile with a radiused nose. Technically, the radius of the nose is ½ of the bullet’s diameter.

Question 27

What instruments can be used to obtain the measurement of the LIMP and GIMP?

Answer 27

• Comparison Microscope – Air gap
• Stereo Microscope – Micrometre
• Comparison Microscope – Microscale
• Software Measurements

Question 28

How to use a comparison microscope - air gap?

Answer 28

1. The bullet and the measuring devices are mounted on stages of the comparison microscope. Both stages must use the same magnification.
2. Adjust the measurement gap (opening) between the jaws (verneer calipers) or spindle/anvil (micrometer caliper) to align with the reference points of the appropriate land or groove impression.
3. Record the value to the nearest hundredth or thousandth of an inch.

Question 29

How to use a stereo microscipe - micrometre?

Answer 29

1. Mount the fired bullet beneath the stereo microscope.
2. Place the land or groove impression of the fired bullet in the topmost vertical position with one of the reference points corresponding with the alignment grid of the micrometer.
3. Rotate the micrometer’s measuring point to the next reference point and record the measured width. Record the value to the nearest hundredth or thousandth of an inch (or appropriate measurement).

Question 30

How to use a comparison microscope - microscale?

Answer 30

1. Mount the fired bullet on one stage of the comparison
   microscope and the microscale on the other stage with both
   using the same level magnification.
2. Ensure that they are in focus on the top center portion of the
   bullet surface and on the microscale markings.
3. Place the land or groove impression of the fired bullet in the
   topmost vertical position with one of the reference points
   corresponding with a mark on the microscale.
4. Record the measured width to the next reference point.
   Record the value to the nearest hundredth or thousandth of
   an inch (or appropriate measurement).

Question 31

How to use software measurements?

Answer 31

1. Mount the fired bullet on the comparison
   microscope.
2. Ensure proper lighting and orientation.
3. Verify calibration of software. Verify proper settings
   are selected
4. Use software to determine land and groove width
   measurements. Record the value to the nearest
   hundredth or thousandth of an inch (or appropriate
   measurement).