Shooting Strategy AI Dialogue

[John Corbett]

The evidence suggests that LHO did some substantial planning for the Walker attempt. Therefore I would fully expect that he had a pretty good estimate of the distance involved with the place that he planned to shoot from. LHO apparently paid extra money for the scope, so it seems to me that he planned to use it for the Walker attempt. With the above in mind, and Marina’s reports of LHO practicing with the rifle, I have to believe that he zeroed the scope for his estimated distance of the Walker attempt (~100’). And I would expect that the scope was still zeroed for that ~100’ distance on 11/22/63.

The iron sights are another story. They are fixed (non-adjustable) at 200-meters if I remember correctly. I will try to find out the exact distance that the iron sights are above the center of the bore and see if I can come up with a ballistics calculation of how far off they would have been at the various distances of the Walker attempt and the distances involved in Dealey Plaza.

The fact that his shot struck the very bottom of the open window sash indicates to me his shot was high of his intended line of fire. Rather than the shot going through the open window, it hit the bottom of the sash. Just an educated guess but I doubt he used the scope for the Walker shooting. The iron sights were fixed and zeroed for 200 meters so at close range, the rifle would aim high. Oswald should have known that but he might have just forgot to make the adjustment.

[Charles Collins]

The fact that his shot struck the very bottom of the open window sash indicates to me his shot was high of his intended line of fire. Rather than the shot going through the open window, it hit the bottom of the sash. Just an educated guess but I doubt he used the scope for the Walker shooting. The iron sights were fixed and zeroed for 200 meters so at close range, the rifle would aim high. Oswald should have known that but he might have just forgot to make the adjustment.

You can believe that if you want to. It makes no difference to me.

The ballistics calculator indicates that using the fixed iron sights on that rifle with that ammo and at a distance of ~33-yards, the point of impact would be ~2.4” high relative to the point of aim.

Personally, I believe using the scope (if zeroed at the proper distance) would be a much better option. Again, it makes no sense to me that LHO would have spent extra money for the scope, practiced (and presumably zeroed the scope for the proper distance), and then for some inexplicable reason decided to use the fixed iron sights which would require a significant hold-under (2.4”) to be on target.

An alternative idea for why the shot might have hit the window sash is the recoil of the short rifle. It is significantly greater than a standard length rifle. If LHO didn’t hold the rifle steady during the follow-through, the recoil tends to raise the muzzle higher and this could have caused the miss. See the original post in this thread for the AI description of this effect.

[John Corbett]

You can believe that if you want to. It makes no difference to me.

The ballistics calculator indicates that using the fixed iron sights on that rifle with that ammo and at a distance of ~33-yards, the point of impact would be ~2.4” high relative to the point of aim.

Personally, I believe using the scope (if zeroed at the proper distance) would be a much better option. Again, it makes no sense to me that LHO would have spent extra money for the scope, practiced (and presumably zeroed the scope for the proper distance), and then for some inexplicable reason decided to use the fixed iron sights which would require a significant hold-under (2.4”) to be on target.

An alternative idea for why the shot might have hit the window sash is the recoil of the short rifle. It is significantly greater than a standard length rifle. If LHO didn’t hold the rifle steady during the follow-through, the recoil tends to raise the muzzle higher and this could have caused the miss. See the original post in this thread for the AI description of this effect.

Looking at the backyard photos, I don't see a scope on the rifle. It might be due to the camera angle but I don't think he had the scope on the rifle when those photos were taken. Whether he used the iron sights or the scope when he shot at Walker, a shot just 2.4" inches high might have made the difference between a clean shot at Walker's head and striking the sash. I think that is a far more likely explanation for the high shot than recoil. The amount of recoil that occurs before the bullet leaves the barrel is negligible and is mostly rearward, not upward. AI describes this much better than I would:

"Yes — a rifle does recoil before the bullet leaves the muzzle, and this movement can affect accuracy.

When the trigger is pulled, the expanding gases from the burning powder begin pushing the bullet down the barrel. By Newton’s Third Law of Motion, the rifle experiences an equal and opposite rearward force almost immediately

. High‑speed videos (100,000+ frames per second) have captured this: the barrel and rifle system move backward while the bullet is still traveling through the bore, even through a suppressor


The bullet’s barrel dwell time — the time it takes to travel from the chamber to the muzzle — is extremely short, often around 0.0006–0.0007 seconds for a 24‑inch barrel at ~3000 fps

. However, the rifle’s inertia means it accelerates more slowly than the bullet, but it still moves during that time. In one calculation, a rifle could move about 0.06 inches rearward during that dwell period

. This movement can cause the muzzle to point slightly off the initial aim point, especially if the rifle is not perfectly supported or if the shooter’s body shifts."

Recoil would have more effect on subsequent shots when firing rapidly but it would not explain Oswald's miss when he shot at Walker. The M-14 was a full-auto version of he M-1 Garand. They soon discovered the problem when firing it in full auto since it used the same .30-06 cartridge. Few soldiers could hold the weapon on target. They found that the first round would be on target, the second, slightly high, the third over the head of he target and by the fourth round, it was an anti-aircraft gun.

The BAR was also a fully automatic weapon that fired the .30-06 round but because it was so much heavier than the M-14, it was much easier to control the recoil.

[Charles Collins]

Looking at the backyard photos, I don't see a scope on the rifle. It might be due to the camera angle but I don't think he had the scope on the rifle when those photos were taken. Whether he used the iron sights or the scope when he shot at Walker, a shot just 2.4" inches high might have made the difference between a clean shot at Walker's head and striking the sash. I think that is a far more likely explanation for the high shot than recoil. The amount of recoil that occurs before the bullet leaves the barrel is negligible and is mostly rearward, not upward. AI describes this much better than I would:

"Yes — a rifle does recoil before the bullet leaves the muzzle, and this movement can affect accuracy.

When the trigger is pulled, the expanding gases from the burning powder begin pushing the bullet down the barrel. By Newton’s Third Law of Motion, the rifle experiences an equal and opposite rearward force almost immediately

. High‑speed videos (100,000+ frames per second) have captured this: the barrel and rifle system move backward while the bullet is still traveling through the bore, even through a suppressor


The bullet’s barrel dwell time — the time it takes to travel from the chamber to the muzzle — is extremely short, often around 0.0006–0.0007 seconds for a 24‑inch barrel at ~3000 fps

. However, the rifle’s inertia means it accelerates more slowly than the bullet, but it still moves during that time. In one calculation, a rifle could move about 0.06 inches rearward during that dwell period

. This movement can cause the muzzle to point slightly off the initial aim point, especially if the rifle is not perfectly supported or if the shooter’s body shifts."

Recoil would have more effect on subsequent shots when firing rapidly but it would not explain Oswald's miss when he shot at Walker. The M-14 was a full-auto version of he M-1 Garand. They soon discovered the problem when firing it in full auto since it used the same .30-06 cartridge. Few soldiers could hold the weapon on target. They found that the first round would be on target, the second, slightly high, the third over the head of he target and by the fourth round, it was an anti-aircraft gun.

The BAR was also a fully automatic weapon that fired the .30-06 round but because it was so much heavier than the M-14, it was much easier to control the recoil.

Looking at the backyard photos, I don't see a scope on the rifle.


The black shirt camouflages the black scope. But it is definitely there. It helps to be looking at a good quality photo. This one is from the Sixth Floor Museum.