All reports: Forward a copy to the Commander, US Army Test and Evaluation Command,
Aberdeen Proving Ground, Maryland.
Local procedures should require accurate dud and misfire records, whether these malfunctions are
reportable or not. See Figure 2-1 for an example of a monthly dud/misfire record.
CALCULATING DUD AND MISFIRE PERCENTAGE RATES
Dud and misfire percentage rates are calculated by dividing the number of malfunctions by the total
number of rounds expended. For example, a using unit expended 30 fragmentation grenades. Two of
these are duds. Table B-1 in AR 75-1 shows that two grenade duds make a reportable number. The
percentage rate is calculated as follows:
2 (duds) 30 (expended) = .07 x 100 = 7%
Table B-1 shows that the reportable defect rate for grenades is five percent. The seven percent rate
exceeds the reportable rate.
Normally, the total quantity used in the calculation will be the quantity fired by the using unit in a
particular day. However, if satisfactory records are kept, a cumulative total for a certain lot fired by
other units on other days may be compiled. Records for time periods of up to 30 days may be used.
For example, a using unit fires 62 mortar rounds and has four duds. This makes a 6% dud rate, which
is reportable according to Table B-1. However, other units over the past 30 days have fired 238 rounds
of the same lot and have had only six duds. Using the total duds and the total rounds, the cumulative
percentage is calculated as follows:
4 + 6 = 10 total duds
62 + 238 = 300 total rounds expended
10 300 = .0333 x 100 = 3.33%
Table B-1 shows that the reportable rate is 5%. The cumulative percentage rate in this case is 3.33%.
Therefore, this dud rate is not reportable.
During this lesson you have learned:
Reporting procedures and requirements and procedures for conventional ammunition duds and
How to calculate failure rates.
You will now take a practice exercise that covers the material you learned in this lesson. When you
complete the practice exercise satisfactorily, proceed to the subcourse examination.