When the firing pin strikes, there is a small explosion. Fire is given off——
Representative Boggs. How does that bring about the explosion?
Mr. Cunningham. It is sensitive to detonation by a sharp blow.
Mr. Eisenberg. That is, the primer is sensitive?
Mr. Cunningham. Yes; it is an explosive. To differentiate from the powder, which is not explosive. Powder burns.
Mr. Eisenberg. Now, I have taken Commission Exhibit No. 591, which consists of an unfired cartridge, and there is a round circle in the middle of the base of that cartridge. Is that the primer?
Mr. Cunningham. Yes. That is actually a separate entity that has been pressed into a hole in the base of the cartridge case.
Mr. Eisenberg. And that is more sensitive to shock than the powder in the cartridge case itself?
Mr. Cunningham. Yes. Powder is relatively insensitive. You don't set off powder by a blow.
Mr. Eisenberg. But the primer is quite sensitive?