Mr. Specter. Let me rephrase the question. Would it be very difficult for a man with Oswald's capabilities as a marksman to use a rifle with a four-power scope?
Sergeant Zahm. No; I feel that the instruction that he had received qualifies him on the basic fundamentals of marksmanship. There are just a few refinements in the operation of the bolt rifle and the scope through a minimum amount of experimenting would make him as proficient with the bolt and the scope as it did with the weapons he received instruction on, and if not it would improve his proficiency actually through the use of the telescope. I feel that this would be an advantage.
Mr. Specter. How many shots in your opinion would a man like Oswald have to take in order to be able to operate a rifle with a four-power scope, based on the training he had received in the Marine Corps?
Sergeant Zahm. Based on that training, his basic knowledge in sight manipulation and trigger squeeze and what not, I would say that he would be capable of sighting that rifle in well, firing it, with 10 rounds.
Mr. Specter. Would dry runs be an aid to a man like Oswald in learning how to operate a rifle with a scope on it.
Sergeant Zahm. Yes.
Mr. Specter. Would you describe for the record what is meant in marksmanship terms by a dry run?
Sergeant Zahm. Dry firing is working the bolt and manipulating the trigger and alining the sights, whether it be scope or iron, without any ammunition. The advantage in the scope in dry firing is that when he snaps the trigger or squeezes the trigger, he can see any apparent error in his trigger manipulation, movement of the piece, by the jump of the crosshair much easier than he can with iron sights.
Mr. Specter. Would the use of a four-power scope be a real advantage to a marksman of Mr. Oswald's capabilities or of a slight advantage, or how would you characterize the advantage that he would obtain, if any, from the use of such a scope?
Sergeant Zahm. I consider it a real advantage, particularly at the range of 100 yards, in identifying your target. It allows you to see your target clearly, and it is still of a minimum amount of power that it doesn't exaggerate your own body movements. It just is an aid in seeing in the fact that you only have the one element, the crosshair, in relation to the target as opposed to iron sights with alining the sights and then alining them on the target. It is a real aid.