Mr. Eisenberg.

mark produced by the rifle through which the test bullets you were given were fired?

Mr. Nicol.

No, sir; I could not.

Mr. Eisenberg.

Now, I am not quite clear as to why another set of marks should have appeared on the other cases, which you also think are extractor marks.

Mr. Nicol.

I cannot say that this could not have been produced by another gun.

Mr. Eisenberg.

That might have been produced by another gun?

Mr. Nicol.

Yes.

Mr. Eisenberg.

But it was produced by the same source, whether it was this gun or another gun, three different times?

Mr. Nicol.

Correct.

Mr. Eisenberg.

Somebody had done one operation, in your opinion, with this cartridge at three different times?

Mr. Nicol.

Right.

Mr. Eisenberg.

Now, just to set this in context, I have taken the bolt from Commission Exhibit 139, the rifle found on the sixth floor, and could you show the Commission what the extractor is on this bolt?

Mr. Nicol.

The extractor is this semicircular piece extending back in the bolt, and its purpose is to withdraw the cartridge from the chamber at the time that the bolt is drawn back. It rides in the extractor groove, which is machined in the head of the cartridge case. At the time that the weapon is loaded, oftentimes this springs around, it first contacts the rim of the cartridge case, and then springs around the rim of the cartridge and produces marks such as these, or marks such as I have illustrated on the three sets.

Mr. Eisenberg.

Now, is it possible that the reason the marks were present on this cartridge but not on the other cartridge case on this cartridge case but not on the other cartridge cases you examined--is because these marks were produced by dry firing as opposed to actual firing?

Mr. Nicol.

This is possible. The weight of the empty shell would be different of course from one which had a projectile in it, so that its dynamics might be different, and it might produce a different mark-- although in the absence of accessibility of the weapon, or the absence of these marks on the tests, I really am unable to say what is the precise origin of those marks, except to speculate that they are probably from the extractor, and that the second mark that appears here, which I have indicated with a similar number, is probably an ejector mark.
Now, this, I might add, is a different type of ejector mark than the mark found on the rim from the normal firing of these tests and the evidence cartridges.

Mr. Eisenberg.

Now, you stated that another mark appeared in all three associated in juxtaposition with the three marks you have been describing?

Mr. Nicol.

Yes; and in the same angular relationship to a radii through the center of the head.

Mr. Eisenberg.

Now, again, if it is an ejector mark, might the difference have been caused by the fact that it may have been associated with a dry firing rather than an actual firing?

Mr. Nicol.

That might be possible.

Mr. Eisenberg.

Do you think a person would apply a different bolt pressure in a dry firing as opposed to an actual firing?

Mr. Nicol.

Well, since this is a manually operated weapon, it is quite possible that no two operations are done with exactly the same force. However, with reasonable reproduceability, all these marks appear to the same depth and to the same extent, so that it would appear that whatever produced them operated in identically the same fashion.

Mr. Eisenberg.

Do you have anything you would like to add to your testimony on the rifle bullets or the rifle cartridge cases, Mr. Nicol?

Mr. Nicol.

No, sir; I don't think so.

Mr. Eisenberg.

If there are no further questions on that particular subject, I will proceed to the Tippit bullets and cartridge cases.

Mr. Dulles.

Off the record.