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The Side Mounted Scope on the 6.5 mm Carcano

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This thread was begun on another forum and I am transferring the posts to here.

ianlloyd wrote:Did its offset mounting make using the open sights a possibility?

Looking at the scope, it looks to be mounted quite high above the weapon, presumably in order to allow operation of the bolt but also to allow the shells to eject without hitting the scope? Does this provide sufficient space beneath the scope to have used the iron sights instead? I've only shot air guns as a kid and used scopes on those sometimes and recall finding it difficult to re-acquire a target (obviously just to look at it after firing to see if I'd hit it). I usually removed the scope as I found it easier with just the iron sights, even more so if tracking a target.

Hello Ian

You bring up a very good point about scopes designed for air guns and low velocity .22 calibre rifles.

The rifle scope mounted on the M91/38 6.5mm Carcano short rifle, allegedly owned by LHO, was an Ordnance Optics 4x18 scope. It was a very inexpensive scope made in Japan and was designed to be mounted on a .22 calibre rifle or an air powered pellet gun. Due to the low velocity of a .22 rifle, it is not a rifle typically used to make 100 metre shots, and target shooting at 25 metres is more in line with its capabilities.

To better understand this scope, it is necessary to define the numbers assigned to it, 4x18. The number 4 tells us that this scope will magnify the size of anything viewed through it four times. The number 18 defines what is known as the "objective lens diameter" and is the diameter of the forward end of the scope that allows light in. The larger the diameter, the more light is allowed to enter the scope and the better defined the target is to the viewer. As stated, this scope was 18 mm in diameter. Scopes designed to shoot 100+ metres usually start at around 32 mm and go as high as 50 mm.

A very important feature of a scope, and the cause of your problems in re-acquiring your target, is a thing known as "field of view". This is usually defined in hunting scopes as the width of the area visible through a scope at 100 metres. Quite simply, some "wide angle" scopes, such as the original Redfield Widefield scopes, made it much simpler to find what you were shooting at by giving you a wider view of what you were trying to look at. I bought a wide angle Bushnell scope for a rifle years ago simply because I could not track a moving deer through brush when viewing it in such a tiny field of view as was seen in the scope I replaced. Now, when you design a scope to shoot .22 calibre rifles at 25 metre targets, field of view no longer becomes a concern for the manufacturer. I remember shooting .22 rifles equipped with similar cheap scopes as a kid, and the field of view was ridiculously small, comparable to trying to find someone in a crowd by looking through a 1/2" tube.

For those who believed Oswald used the open sights on 22/11/63, here is a good question. If Oswald practiced shooting this rifle as much as some claim he did, he would have noticed the inadequacies of the scope re: field of view immediately. Wouldn't it be likely that he would have removed the scope prior to bringing the rifle to the TSBD, if he knew he was going to be using the open sights?

More to come......

Edited by Robert Prudhomme
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To better understand the difficulties of sidemounting a scope on a rifle, there are a few more things about rifle scopes you should know. Look carefully at the following two diagrams:



These may look a bit complicated but are really quite simple. When a bullet leaves the muzzle of a rifle, the only force acting on it then is gravity, and it will begin falling to the earth. For this reason, to hit a target at 100 or 200 metres by aiming at it through a scope (or sights), it is necessary to raise the barrel up so the bullet will follow a parabolic curve to the target and impact the target on descent. The amount of elevation depends upon how "flat shooting" the rifle is. A rifle with a high muzzle velocity and a high ballistic coefficient will not require much elevation, while a low velocity round with a bullet possessing a low ballistic coefficient (the 6.5mm Carcano M91/38, for example) requires more elevation.

Quite often, on a hunting rifle, the line of sight will be adjusted until the rifle is able to hit bullseyes at 200 metres. This does not mean the hunter is specifically looking for game at 200 metres, although his rifle is sighted in for that distance. The purpose of this is that his rifle, at 100 metres, will only be shooting an inch or two high at the top of the parabola and this can be easily compensated for, much easier than trying to hit a target at 200 metres with a rifle sighted in for 100 metres. The results can be seen in this chart. Note how quickly the bullet begins to drop.


It should be noted that C2766 was an M91/38 short rifle, and that its rear sight was not adjustable, but fixed at 200 metres (219 yards). If C2766 was a high velocity flat shooting rifle, a bullet impacting the bullseye at 200 metres would only be an inch or so high at 100 metres. However, this was not the case with C2766, and the ballistics calculator we used in another thread shows that a Carcano 6.5mm bullet, with a muzzle velocity of 2165 fps, impacting a bullseye at 200 metres, would be just over 7 inches high at 100 metres. This is a serious consideration for the "Oswald did it all with open sights" advocates.

It is interesting to note, from the first two diagrams, that the bullet path will cross the line of sight just a few metres out from the muzzle, and again at the target. This actually means that a rifle sighted in to be accurate at 200 metres is also accurate at a few metres.

Now, while the trajectory of a rifle seriously affects hitting the height of a target at different ranges, and this was the inspiration for built in rangefinders on hunting scopes, the advantage of mounting a scope (or open sights) directly above the barrel of a rifle is that the left-to-right (windage) of line of sight to bullet impact relationship does not vary with range. In other words, if you aim at bullseyes at 50 metres, 100 metres, 200 metres and 300 metres, you will see a corresponding drop of the impact point of the bullets as you go further out but, unless you are shooting in a crosswind, there will be no variation to left or right on the target.

However, if you mount the scope on the side of the receiver, as on LHO's alleged rifle, you are no longer directly over the barrel. Even though it appears to be too small of a space to make much difference, the line of sight (from the scope) and the line of departure (bullet path) are now beginning from two different points, and the rifle can only be sighted in for windage to be accurate at one range and one range only; namely, the point at which these two lines converge. Any close shot made with this rifle will put the bullet to the right of the aimed at target, and any shot made past the convergent point will put the bullet to the left of the aimed at target.

Years ago, a friend of mine owned a Winchester Model 94 30-30 lever action rifle. It had open sights and was a great deer rifle in brushy ground. For some odd reason, my friend decided one day he just had to have a scope on this rifle, even though he was a deadly shot with open sights. As with the Carcano, it was necessary for the gunsmith to side mount the scope on the 30-30, not because of interference with the action but because this repeating rifle ejected cartridges straight up from the receiver, and they would hit the scope.

The gunsmith "boresighted" the scope after mounting it but, of course, it was still necessary to sight the rifle in at the range as boresighting only "gets you on the paper", as they say. It almost drove us insane trying to sight that rifle in so it would hit bullseyes at 100 metres. Every adjustment we made to elevation or windage seemed to throw us off somewhere else. It didn't help that the Model 94 is a very light rifle and likes to kick, and one is anticipating this with each shot.

During this exercise, I tried a couple of shots with the open sights, and found having the scope right in your face made this an extremely awkward and uncomfortable thing to do. As I said before, those who think the inadequacies of the scope would have prompted LHO to use the open sights during the assassination are as much as saying LHO never practiced at a range with this rifle. If he had, he would have removed the scope long before he brought the rifle to Dealey Plaza.

Edited by Robert Prudhomme
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In basic training in the USMC, Lee Harvey Oswald would have been issued a 30-06 calibre M1 Garand. This was an eight round, semi-automatic, "en bloc" clip fed rifle that was equipped with a type of iron sights known as a "peep sight". There is no evidence to show that Oswald, in basic training or later on, ever received any training in shooting and maintaining a scope mounted rifle.

It is interesting to note the similarities between the 6.5mm Carcano and the M1 Garand. Both used an "en bloc" charger clip, six round for the Carcano and eight round for the Garand. The Carcano clip fell out of the bottom of the magazine when the last round was chambered and the Garand clip was ejected out the top of the magazine when the last round was fired. Neither of these rifles could have a scope mounted directly over the receiver. The bolt of the Carcano would have struck a scope in this position, and the Garand ejected its empty cartridges upwards (like the Winchester Model 94 I spoke of). In some cases, scopes were side mounted on the Garands on the left side of the receiver, and, in others, scopes were mounted ahead of the chamber and directly above the barrel, to overcome the problems I spoke of in my last post. Suffice it to say that shooting with a scope mounted ahead of the chamber would be awkward, at the least.



Also, note the difference between these long range scopes and the pathetic .22 calibre scope mounted on Oswald's alleged rifle.

As the M1 Garand is a very accurate fast shooting weapon and its peep sight makes target re-acquisition very easy following a shot being fired, I have often thought to myself that the Lone Nut story would have been much more believable if the rifle found on the 6th floor had been a Garand. This was, after all, the rifle Oswald had trained with, and its semi-automatic action would have allowed more than three shots to be fired in the time allotted.

Here are a couple of Youtube videos that demonstrate how quickly an M1 Garand can be fired with accuracy.


Edited by Robert Prudhomme
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From the Warren Commission testimony of FBI Special Agent Robert A. Frazier:

"Mr. FRAZIER - Yes, sir. We fired additional targets at 100 yards on the range at Quantico, Va., firing groups of three shots. And I have the four targets we fired here.
Mr. EISENBERG - Mr. Chairman, I would like these admitted as 551, 552, 553, and 554.
Mr. EISENBERG - Who fired these shots, Mr. Frazier?
Mr. FRAZIER - I fired them.
Mr. EISENBERG - Can you characterize the dispersion on each of the four targets?
Mr. FRAZIER - Yes, sir. On Commission Exhibit 551 the three shots landed approximately 5 inches high and within a 3 1/2-inch circle, almost on a line horizontally across the target. This target and the other targets were fired on March 16, 1964 at Quantico, Va. These three shots were fired in 5.9 seconds. The second target fired is Commission Exhibit 552, consisting of three shots fired in 6.2 seconds, which landed in approximately a 4 1/2 to 5-inch circle located 4 inches high and 3 or 4 inches to the right of the aiming point. Commission Exhibit No. 553 is the third target fired, consisting of three shots which landed in a 3-inch circle located about 2 1/2 inches high and 2 inches to the right of the aiming point. These three shots were fired in 5.6 seconds. And Commission Exhibit No. 554, consisting of three shots fired in 6.5 seconds, which landed approximately 5 inches high and 5 inches to the right of the aiming point, all within a 3 1/2-inch circle.
Mr. McCLOY - The first one is not exactly 5 inches to the right, is it?
Mr. FRAZIER - No, sir. The center of the circle in which they all landed would be about 5 inches high and 5 inches to the right.
Mr. EISENBERG - Mr. Frazier, could you tell us why, in your opinion, all the shots, virtually all the shots, are grouped high and to the right of the aiming point?
Mr. FRAZIER - Yes, sir. When we attempted to sight in this rifle at Quantico, we found that the elevation adjustment in the telescopic sight was not sufficient to bring the point of impact to the aiming point. In attempting to adjust and sight-in the rifle, every time we changed the adjusting screws to move the crosshairs in the telescopic sight in one direction-it also affected the movement of the impact or the point of impact in the other direction. That is, if we moved the crosshairs in the telescope to the left it would also affect the elevation setting of the telescope. And when we had sighted-in the rifle approximately, we fired several shots and found that the shots were not all landing in the same place, but were gradually moving away from the point of impact. This was apparently due to the construction of the telescope, which apparently did not stabilize itself--that is, the spring mounting in the crosshair ring did not stabilize until we had fired five or six shots."

For a firearms expert, Mr. Frazier has an odd way of describing things. For example, the shots were "gradually moving away from the point of impact." Unless there was some sort of magic at play here, I think I would have said they were moving away from the point of "aim", not impact.

Speaking of magic, I do not think I have ever heard of a rifle scope that required a few shots being fired to allow it to "stabilize" itself. This would be akin to changing the TV channels with a remote control and then having to bang on the side of the TV until the channel changer responded. What would happen if you hit the TV one too many times? Would it go past the desired channel? If what Frazier says is true (and I think it is nonsense), each time the rifle scope is jarred, it will take several shots to "re-stabilize" it. Once again, we have the FBI relying heavily upon the ignorance not only of the WC but also of the American public.
In fairness, though, it should be pointed out again that the 4 x 18 Ordnance Optic scope was designed to be used on pellet guns and .22 calibre rimfire rifles, and it has been reported by many rifle owners they do not stand up well to the jarring from larger calibre rifles.

However, the tendency of successive shots to "walk away" from the point of aim is a common problem with rifles, and it has absolutely nothing to do with the rifle scope. In fact, I experienced this myself, and the cure was quite simple.

As rifle stocks are made from wood, they are prone to absorbing moisture. If you live in a humid climate, such as the temperate rainforest I live in or the city of New Orleans, where LHO resided, this wood can be exposed to tremendous extremes of moisture. In my case, I would go from long hunts on foot in the rain to a nice warm house heated with firewood. I would wipe my rifle down, clean it and then hang it on the wall next to a wood fired heater.

Suffice it to say, it only took a few cycles of this wet/dry before the wooden forestock of my rifle warped on me. It first became apparent when I could not hit what I was shooting at. I took the rifle to the range and found, at 100 metres, it was hitting, on the first shot, slightly high and to the right of the bullseye. Each successive shot hit higher and more to the right, until I was easily six inches from the bullseye.

The barrels of most rifles "float" in their forestock, meaning that they are attached to the stock only at the chamber. This can be demonstrated by wrapping a piece of paper half round the barrel and sliding it between the barrel and the forestock. There should be no contact and the paper should pass easily between barrel and forestock, right up to the base of the barrel where it meets the chamber. If it does not, you have a problem that needs to be corrected.

In the case of this rifle, I found, at the front end of the forestock, the forestock had warped and was pressing tightly against the lower left side of the barrel. Believe it or not, this small amount of pressure was enough to slightly bend the barrel upwards and to the right, making the first shot land high and to the right of the point of aim, and progressive shots hit higher and further to the right of the point of aim. When I fired the first shot, the barrel heated up, expanding the metal, and the increased pressure caused the barrel to bend more. Each successive shot would bend the barrel even more as the temperature of the barrel increased.

The solution, of course, was simple. I removed the stock and sanded that part of the forestock that was contacting the barrel until I had re-established the necessary clearance, applied sealant to prevent it absorbing more moisture and re-assembled the rifle.
Edited by Robert Prudhomme
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Your point, Robert, about Oswald's never having received in basic training instruction with a scoped rifle rings true.

As an ROTC cadet and later as a U.S. Army officer, I received instruction in how to fire a number of weapons: the M-14, the M-16, the grenade launcher. the M-60 machine gun. Later I fired the M-1A carbine, the grease gun, etc.

I came across the AK-47 and the Swedish K-gun in Nam.

At no point was I instructed in how to use a scope. Only open sights.

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Thank you for this thread, Robert. I don't know if anyone on this ed-forum, jfk section, has ever done an in depth study of the scope on the carcano before.

I'm not a shooter so I hope you'll bear with some newbie q's. I assume any drift from the spin of the bullet is insignificant. Ditto anything from the wind gusts. I've read that targeting downwards is significantly different from shooting upwards and level. A scope set using a level range will not suit when shooting down. (?)

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Hi John

A side wind is definitely something that has to be compensated for once you start shooting at the longer ranges. There are tables available on the Internet that will show you how much drift takes place in a crosswind, given the range you are shooting and the speed of the cross wind.

It is a little known fact that if you sight a rifle in on level ground to be accurate at, let's say for example, 100 yards, and then shoot at a target 100 yards away uphill OR downhill, the bullet will, in both cases, go high of the point of aim.

Edited by Robert Prudhomme
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This is a great thread and very informative. I have always had the same thoughts re the presence of the scope - if it was easier to fire without the scope then any experienced shooter wouldnt have had the thing anywhere near his set up... the presence of the scope however also provides the Commission report with some nice reconstruction close ups of a mock Kennedy (magnified) which makes the shot look much easier than it would have been minus a "quality" scope.

Also, from reading about this alleged shooting feat for many years it always appears odd that there can such an apparent divergence of opinion from firearms experts:-

On one hand there is the opinion that this would be an extremely difficult feat given the various factors (quality and set up of weapon, firing position, moving target, cross winds, gradient, distance, etc) not to mention the planning, discipline, skill to make the shots, not to mention the cool headedness required to miss completely with your free shot before achieving two almost perfect hits. Then there is the difficulty that the Commission appointed experts had in replicating the shots with the scope as has been pointed out.

On the other hand you have others saying that this was an easy shot, from close range, slow moving target, more than capable rifle in the carcano, etc... there doesnt seem to be any middle ground?

Edited by Russ Connelly
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