Burrard's protocol for the diagnosis of a burst
In order to give the investigator every possible chance of arriving at the truth the gun should be sent up for examination as soon as possible, and without being cleaned. Accompanying the gun should be the fired case of the cartridge which actually cause the burst; if possible the fired case of the round immediately preceding the burst, a few fired cases, and as many unfired cartridges as possible…of the batch which was being used at the time.
With this evidence available it should be possible to diagnose the cause of the accident with certainty. By far the most common cause of burst is some obstruction in the bore, and so the first thing to do is to look for evidence of an obstructional burst, that is for a ring bulge. If a ring bulge is detected the cause of the burst becomes established beyond any shadow of doubt.
Every effort should be made to try to ascertain what the obstruction could have been; and in this connection the owner of the gun should be asked to give replies to the following questions:
1. Was the accident caused by the first shot of the day through the barrel which actually burst?
2. If the accident was not the result of the first shot of the day, what was the result of the shot from the barrel which burst immediately previous to the one which caused the damage?
3. Did anything in the least abnormal occur in the case of the shot fired through the burst barrel immediately before the round which caused the burst?
4. Was the chamber apparently empty when the gun was opened for re-loading (prior to the burst)?
5. Was any member of the party using a smaller bore of gun? What size?
6. Does the shooter own a gun and cartridges of smaller gauge than the one which burst?
7. Under what conditions was the shooting taking place?
8. What was the nature of the ground on which the shooter was standing or walking at the time of the accident?
The answers to these eight questions and the actual position of the burst in the barrel should between them provide sufficient data to determine the nature of the obstruction with comparative certainty. But the fired case of the round which caused the burst and also that of the round immediately preceding the burst should also be examined for confirmatory evidence.
In order to complete the investigation a most careful examination should be made of as many live cartridges as possible from the same batch. Some should be opened, and the weights of the powder and shot charges checked in order to test for regularity of loading.
Then all the remaining cartridges should be tested for ballistics; that is pressure and velocity, and if possible recoil.
Then a most careful examination should be made of the fractured edges (and) the thickness of the wall…
(This is where the formal failure analysis and metallurgical study starts).
Wernher von Braun "One test result is worth one thousand expert opinions"
