(Testimony of Robert A. Frazier)
Mr. Frazier.
that it points the scope at the target closely enough to permit adjusting the crosshair to accurately sight-in the rifle.
Representative Boggs.
One other question, then. "
It is possible, is it not, to so adjust the telescopic sight to compensate for that change in the target?
Mr. Frazier.
Oh, yes. You can accomplish that merely by putting shims under the front of the scope and over the back of the scope to tip the scope in the mount itself, to bring it into alinement.
Representative Boggs.
So an accomplished person, accustomed to using that weapon, anticipating a shot of that type, might very well have made such an adjustment prior to using the rifle; isn't that so?
Mr. Frazier.
If it were necessary; yes. There were no shims in the weapon, either under the mount, where it screws to the weapon, or in the two mounting rings, when we received it in the laboratory.
Mr. Eisenberg.
Do you have any shims with you, Mr. Frazier?
Mr. Frazier.
Yes. When we received the weapon yesterday, there were shims mounted in the rifle. The one under the front end of the mount is in this envelope.
Representative Boggs.
But they were not there when you received it originally?
Mr. Frazier.
No, sir. These were placed there by some other individual.
Mr. Eisenberg.
For the record, these were placed by the ballistics laboratory of the Army, a representative of which will testify later.
Now, turning to another possible source of error in aim, Mr. Frazier, if a rifle such as Exhibit 139 is sighted- in with the use of a target at a given distance, and it is aimed at a target which is further away or closer than the target which was used for sighting-in purposes, will any error be introduced by reason of the fact that the target is further or closer away than the sighting-in target?
Mr. Frazier.
Yes, it will, because the bullet in leaving the muzzle follows a curved path rather than a straight path, and in order to hit a specific target at a specific range, it is necessary for the bullet to travel up and drop down to the target, rather than have the bore pointed right at the target at the time of discharge.
Mr. Eisenberg.
Can you calculate the amount of error which would be introduced by a specific projectile?
Mr. Frazier.
Yes.
Mr. Eisenberg.
Have you made such calculations?
Mr. Frazier.
I have taken calculations for similar weight and velocity bullets from ballistics tables, which bullets approximate the velocity of the 6.5 mm. bullet and the weight of that bullet as fired from 139.
Mr. Eisenberg.
Are these results affected by the rifle which is employed, or do they depend upon the missile?
Mr. Frazier.
They depend upon the weight and shape of the missile and the velocity, but not upon the weapon.
Mr. Eisenberg.
Could you give us the results of these calculations?
Mr. Frazier.
Yes, sir; if you, for instance, take this rifle with a telescopic sight and sight it in for 300 feet--that is, the bullet will strike where you are looking when you are shooting at 300 feet--at 200 feet the bullet will be above the line of sight approximately one-quarter of an inch, and at 100 feet it will be approximately one-quarter of an inch below the line of sight. That is accomplished because the bullet is still coming up at 100 feet, it crosses the line of sight, and does not descend again to it until you come to the sighting-in distance of 300 feet.
If you sighted-in to strike at 450 feet, the bullet at 100 feet would be just at the line of sight--that is, on its way up would just cross the line of sight at about 100 feet. It would be one inch high at 200 feet, and approximately one and one-eighth inches high at 300 feet.
It would, of course, drop back down to the point of aim at 450 feet. If you sighted-in at 600 feet, then at 100 feet it would be approximately one-half inch high. At 200 feet it would be 2 inches high, and at 300 feet it would be approximately 3 inches high.
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