(Testimony of Joseph D. Nicol)
Mr. Eisenberg.
Now, you say burr. This is a burr in the barrel of the rifle which produced--
Mr. Nicol.
No, I believe it is the result of a displacement of metal as the land impresses into the jacket material, and actually machines up a burr along here on the driving edge.
Mr. Eisenberg.
So is there an extrusion on--on the rifle barrel which would produce that?
Mr. Nicol.
It may have been true at one time. It appeared at some point in the passage through the barrel, this portion of the jacket curled up and subsequently before it left the barrel was touched by the rifling, so that it is now flat and even. When I refer to it as a burr, it is not raised up. It is even with the rest of this surface. But you can see the definite outline of that burr at the land edge.
(At this point the Chairman entered the hearing room.)
Mr. Eisenberg.
Now, would this be caused by an extrusion in the barrel or a concavity in the barrel?
Mr. Nicol.
It is probably the result of erosion back at the chamber, back at the rear of the barrel, along the land edge here, and then as the bullet gets to the end of the barrel, pressures decrease, so erosion also decreases, and therefore there is still rifling enough left to press this clown and make some impression on the projectile itself.
Mr. Eisenberg.
And does this lie within a land impression, or the edge of a land impression?
Mr. Nicol.
It would, be actually in the groove impression.
Mr. Eisenberg.
In the groove impression of the bullet?
Mr. Nicol.
Of the bullet.
Mr. Eisenberg.
Now, you found this same mark on the Walker bullet as you found on the bullets that were
Mr. Nicol.
All the Q specimens and the K specimens had this characteristic burr. Now, I could not honestly say that this would not be found, the burr would not be found on other weapons of similar construction, similar velocity. However, the fine lines that you can see visible in this photograph, by which an identification could be made, would be the same individual characteristics as any other fine lines on the rifling impression.
Mr. Eisenberg.
Now, Mr. Nicol, was this burr in the same position in its relation to the edge of the groove on what we have been calling the Walker bullet as it was in the other bullets?
Mr. Nicol.
Yes, sir. And, as a matter of fact, repeated in about the same extent in those land positions and groove positions which are still visible on that projectile.
Mr. Eisenberg.
So that you not only have the existence of the burr, but you have it at a characteristic distance from the edge of a groove impression?
Mr. Nicol.
Correct. And while the contour matched, this is not as significant, because any two guns manufactured with the same rifling cutter, as perhaps a production wealth like this would be, would have the same contour characteristics. So this would not necessarily be definitive. But the presence of those individual characteristics which are referred to, although not sufficient for a positive, certainly would indicate that there is a possibility that this is fired from that particular gun.
Mr. Eisenberg.
Were you able to secure photographs of this Walker bullet under the microscope?
Mr. Nicol.
No; I could not, because what I would be comparing would be a curved surface that is flattened out with the test bullets, which would be still in curved geometry. So that while I might get one point in match, the others, you see, would be spread out. So that--actually, an identification of that kind is made in a dynamic fashion. That is to say, one bullet is slid and the other bullet is rotated. So that it is in a sense unfolding the curved bullet so teat it resembles in a progressive way the flattened out projectile.
Mr. Eisenberg.
Mr. Nicol, I now hand you Commission Exhibit--well, before I go into that, is there any further testimony you wish to give on the subject of the rifle bullets?
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