Telescope Sights


Telescope Sights

by Townsend Whelen
The American Rifle (The Century Co., New York, 1918)

A telescope sight is a small telescope having cross wires similar to a surveyor’s transit, and is mounted on the barrel of the rifle in such a manner that in aiming in the usual manner one’s eye looks through the telescope at the object. The object is magnified by the telescope, and it is only necessary for the riflemen so to move the rifle that the cross-hairs are superimposed on the particular place that he wishes his shot to strike. The tube of the telescope is made of steel. Two methods of adjustment are in vogue. The commonest is to elevate and deflect the tube by an adjustable rear mounting in exactly the same manner that the rear sight is ordinarily adjusted. The method of elevating and deflecting must allow for very close adjustment, as the front and rear mountings of the telescope are so much closer together than are ordinary front and rear sights. The other method is to depress the cross-hairs by means of a screw and dial, which in effect causes one to aim higher. As a rule the first method is preferable as being more positive and accurate. The chief advantages claimed for the telescope sight are:

(a) It greatly reduces the errors of aim. The error of aim with the best iron sights used by marksmen with perfect vision is 1 inch per 100 yards — that is, for example, 5 inches at 500 yards. The eye cannot see to aim closer than this at the various ranges. With the telescope sight this error is divided by the magnifying power. For example, with a telescope sight magnifying 5 diameters, the error of aim at 500 yards would be only about 1 inch, depending slightly upon the fineness of the cross-hairs, and whether any mirage was present in the air.

(b) It allows objects to be seen more distinctly than with the naked eye. Also it permits the vision to penetrate into places where it could not otherwise, as, for instance, into the edge of a woods, and into dark places that appear perfectly black when viewed with the naked eye.

(c) Low power telescopes with large bright fields permit aim being taken in lights when the iron sights cannot be seen at all. With a good 3-power telescope sight one can see to aim accurately on moonlight nights.

(d) Various forms of telescope sights have certain other advantages which will be discussed later, together with the disadvantages.

A good telescope sight is quite expensive, and it is to a certain extent a delicate instrument. The whole object of equipping a rifle with one is to attain better accuracy than can be had with iron sights. The telescope sight will be here considered primarily as an instrument with which we wish to attain a greater accuracy of aim by (a) eliminating the errors of aim, and (b) making the object aimed at more distinct.

Anything which does not reduce, or actually increases, the error of aim is entirely out of place in connection with a telescope sight. For example, a set of mountings which will not adjust, or are capable of being read closer than, say, 3 inches at 100 yards, is entirely out of place because it introduces an error of as much as 3 inches at times, and this is three times larger than the error of the unaided eye, and fifteen times larger than the error of a good, 5-power, telescope sight.

It will be made evident in the course of this chapter that no telescope sight has ever been produced that is entirely satisfactory for either military use or for big game shooting. Our telescope sights have all been constructed with a view to target shooting, and foreign telescope sights with a view to sale only, and not for use under service conditions. The purpose of this chapter will, therefore, be not so much to describe existing American models, as to discuss the design, capabilities, and development of telescope sights suitable alike for target shooting, war, and sport.

For the sake of brevity the telescope sight adapted to the aiming of rifles will here be referred to as a “scope,” a term in common use among American riflemen.

Power and Field
The power of a scope is its ability to magnify objects seen through it. A 5-power scope magnifies objects five times or diameters, or makes the object appear five times nearer than it actually is. To determine the power of a scope, look through it at a brick wall or similar object. Keep the other eye open, and so move the scope that the image seen through it is alongside the image seen by the naked eye. Count the number of bricks seen by the naked eye which line up against one brick seen through the scope. The result will be the magnifying power.

The field of a scope is the area embraced by the object seen through it when the eye is at the correct distance from the eye-piece. It is usually designated by the diameter at a certain range. To determine the diameter of the field, choose a level piece of ground. Drive a stake A at 100 yards from the scope. Have the scope in a steady rest, and so directed that the stake can just be seen at the left edge of the field of view, on line with a horizontal line passing through the center of the field. Have an assistant drive a second stake B, also 100 yards from the scope, to the right of stake A so that it can just be seen at the right edge of the field of view. The distance from A to B will be the diameter of the field at 100 yards. Twice this will be the diameter at 200 yards, and so on.

It is a law of optics that, other things being equal, the higher the power of the telescope the smaller the field of view.

A high-power scope is best for experimental work and rest shooting, as the error of aim is less. High power and fine cross-hairs are required for absolute alignment, particularly at ranges of 200 yards and over. High-power scopes are usually classified as those magnifying over 6 diameters. Scopes of over 20 diameters are seldom seen. High-power scopes have small, dark fields, and are unsuitable for either military or hunting use.

Low-power scopes, from 2 to 6 diameters, have brilliant and large fields. Objects can be seen distinctly in poor lights. The scope and rifle can be held steadily enough offhand so that the object aimed at remains in the field all the time, and is not continually bobbing in and out of view as is the case with a high-power scope held offhand. Low powers are best for military use, ordinary target shooting, and hunting. There is a little error of aim, particularly if the cross-hairs are very coarse, but the error is always much less than with iron sights.

A scope having a large object lens, and large eye lens in proportion to the distance between the lenses, will have a larger and brighter field than a similar scope of the same power but relatively smaller lenses.

The field of a very high-power scope appears dark; that is, the object viewed through it appears in a darker light than it does when viewed with the naked eye. On dark days such a glass is useless except against a light background, as, for example, a white target. For making the object aimed at appear more distinctly, particularly in poor lights, a scope of low power should always be chosen.

The diameter of the field has considerable to do with the efficiency of the glass for the ordinary uses to which a rifleman will put it. With a glass having a large field the rifleman throws the rifle to his shoulder in such a manner that it points as closely as possible at the object he desires to hit. The object is then surely seen in some part of the field, and it is only necessary so to move the rifle that the cross-hairs superimpose their intersection on the point one desires the shot to strike. With a small field the rifleman may not be able so accurately to throw his rifle to his shoulder that the object will be included in the field of view, but after placing the rifle at his shoulder he may have to swing the rifle up or down, or to one side or another, until he finds the object in the field. This takes time and makes the catching of the aim slow. Moreover, if the field is very small the slight tremors of the rifle and scope, as the rifleman endeavors to hold them steady, may be sufficient to cause the object to be constantly appearing and disappearing in the field. Twenty years’ experience with a large number and variety of scopes has shown that a field of view of at least 20 feet in diameter at 100 yards is essential if the object is surely to be seen in the field when the rifle is thrown to the shoulder by a skilled rifleman. This is a slightly larger field than obtains with any scopes at present made in the United States.

The relief of a scope is the distance at which the eye must be held in rear of the eye-piece in order to obtain the clearest view of the field and its largest diameter. It is greater with scopes than with other forms of telescopes, as it is necessary that the eye be held at some little distance from the eye-piece so that the eye-piece will not strike the eye when the rifle recoils. Also there is a certain latitude to it so that, for example, the eye may be held at any point from 1 1/2 to 3 inches from the eye-piece and still see the field at its best. This form of relief we will call the “longitudinal relief.” A scope for use on a rifle having heavy recoil should have a long longitudinal relief so that the eye will not be endangered. Considerable latitude in the longitudinal relief is always desirable as the eye then does not have to be so accurately placed as to distance from the eye-piece in order to embrace the full field. Latitude thus makes for a quicker catching of the aim and for easier adaptability to the various firing positions. The eye, for example, will be held much closer to the eye-piece naturally in the prone position than it is in the standing position.

There is also another form of relief which we will call the “lateral relief,” that is, the distance which one may move his eye to one side or the other, or high and low, and still see the whole field of view. With iron sights there is no lateral relief at all, and one must get his eye exactly in the line of sight in order accurately to align the front and rear sights. With a telescope there is a certain latitude in this respect, and one may move his eye a little in any lateral direction and still see the whole field of view without disturbing the alignment of the cross-hairs. The more latitude there is to this lateral relief the quicker can the aim be caught, as the eye does not have to come exactly into the line of sight to obtain an accurate aim.

In Fig. 60 the oval in rear of the eye-piece illustrates the relief of the scope. The drawing shows a longitudinal relief of 2 inches, and a lateral relief of 1/4 inch, A-A being the longitudinal relief, and B-B the lateral relief.

The eye can be placed anywhere within the oval and still see the entire field of view, and accurate aim be taken. The optical principle is such that the slight shifting of the eye from side to side through the lateral relief does not alter the line of aim, provided the cross-hairs of the telescope are in proper focus. That the cross-hairs are in proper focus can always be told by fastening the scope in a heavy vise. See first that the cross-hairs appear distinctly, then move the head from side to side through the lateral relief, and notice whether the cross-hairs move at all in their alignment on an object in front of the scope. If they do not move the focus is correct. A scope is absolutely useless unless the cross-hairs are in focus. Some scopes have the cross-hairs fixed immovable and in focus all the time. Others have a screw which allows them to be focused.

It will be obvious that with a relief, as illustrated in Fig. 60, aim can be caught very quickly as the eye does not have to come to exactly one place to get perfect alignment. In fact, with such a relief, and a large field, aim can be caught very much quicker than with any form of iron sights, provided that the scope is so mounted on the rifle that the comb of the stock helps to lead the eye into the line of sight by offering a guide or measure as to about where to place the head to get the eye into the line of sight. As a rule the scopes manufactured in the United States have a rather small longitudinal relief, and entirely too small lateral relief. They are thus suitable only for slow target use and experimental work, such as accuracy testing.

The field of view should be well defined and free from color fringes. This demands good achromatic lenses. This matter is always attended to by the makers with all but the very cheapest scopes, so that it needs no further attention other than to caution the purchaser against cheap scopes with ordinary lenses which will prove absolutely unsatisfactory, and probably introduce eye strain. The mounting of the lenses in the tube is of the greatest importance. Every lens has its optical center, and this may or may not correspond to, and be in alignment with, the axis of the tube. In fact, it is a very expensive matter to make a scope where these two centers coincide. Nor is it necessary for the ordinary uses to which a scope is usually put. If a telescope in which the optical centers of the lenses and the axis of the tube do not coincide be revolved on the axis of the tube, the cross-hairs, instead of remaining aligned on one spot on the target all the while, will pass in a circle over the field of the target. However, in aiming with such a scope the horizontal cross-hair assists one in holding the scope level, and prevents any tendency to rotate or cant, and thus the line of aim remains constant. But if a lens should start to revolve in its mounting in the tube the line of sight would be thrown off with it, and we would have a constantly changing line of sight as the lens revolved. An experience with a German scope several years ago will suffice to illustrate this point. The tube of this scope was divided into two portions. The rear portion revolved, screwing in and out for focus. The two portions were held fast by a set screw. No single set screw can be relied upon to hold with a high-power rifle of heavy recoil. In firing this scope on a high-power rifle it was noticed that the rifle was continually shooting high and to the right. In ten consecutive shots at 200 yards the point of impact, starting at the center of the bull’s-eye, moved two feet during the string towards 10 o’clock. Investigation proved that the rear portion of the tube was revolving during recoil, the set screw not holding it. This, of course, caused the rotation of the eye-piece, and as a consequence the line of sight went sailing up towards 10 o’clock. The glass was properly focused and the two portions then soldered up, and no further difficulty was experienced for a while, until finally the same thing occurred again, and after considerable investigation it was found that one of the lenses had become loose in its seat, being simply crimped therein by little brass flanges bent down over the edges of the lens, and this glass was revolving under the vibrations of recoil and shifting the line of sight a little with almost every shot. These faults are found in almost all German scopes, and make them absolutely unsatisfactory, although their optical properties are superb and often entice riflemen into purchasing them.

A Springfield sporting rifle with German telescope sight attached. A fine appearing combination to the novice, but absolutely useless for practical purposes.

The lenses should all be mounted in barrels which are secured in the tube against rotating by means of a rib on the inside of the tube, and a slot cut in the barrel so that the barrel cannot rotate in the tube. Then there should be a similar rib in each barrel and a cut in the edge of the lens fitting over this rib. Then the lenses cannot rotate. Some arrangement must also be made to prevent the caps which secure the lenses in the barrels from coming unscrewed and making the lenses loose in their seats. It must be remembered that with the peculiar recoil of the high-power rifle single screws will always, sooner or later, become loose.

The mountings of the scope are by no means the least important feature in connection with this instrument. It cannot be impressed too strongly upon riflemen who have had no experience with scopes that the mountings must permit of very close and positive adjustment for both elevation and windage, and must have an arrangement for giving a clear reading of the various adjustments. The smallest movement or distance that the unaided eye can well measure or appreciate is just about .01 inch. Suppose we have Lyman sights on our rifle, the sights being 28 inches apart. With the eye alone we can adjust this sight as close as .01 inch. A change in adjustment of .01 inch on such sights means a change in the point of impact at 100 yards of 1.286 inch. This is plenty close enough in this case. But suppose we have a scope with a short tube (all modern scopes have short tubes) and the distance between the front and rear mountings is only 7.2 inches. Then the smallest adjustment we can see to make on this mounting, that is .01 inch, will cause a change in point of impact of 5 inches at 100 yards. In other words, with the ordinary crude sliding mountings often sold for telescope sights we cannot adjust our sights to shoot closer than five inches at 100 yards, and moreover we can at no time be sure that our rifle is going to shoot correctly at any given object closer than 5 inches. This, of course, will be absolutely unsatisfactory.

The only satisfactory method of adjustment of a scope mounting is by means of micrometer screws having small but positive readings. One who has never used a micrometer very often has the idea that such adjustments are weak and complicated. The fact is they are just the contrary, being nothing more than large, strong screws with the scales engraved on them. A mounting with micrometer adjustments is the simplest and strongest of all kinds. With micrometer adjustments we can easily arrange our mountings so that both the elevation and windage adjustments can be positively moved and read to a change in point of impact of half an inch at 100 yards, or in other words half a minute of angle.

A scope has two mountings, front and rear, corresponding to the front and rear sights. The front mounting has no adjustment, but holds the scope so that it can be moved slightly at the rear end in any direction. The rear mount should have adjustments for both elevation and windage. The only scope mountings made in the United States, or in fact in any country, which are at all satisfactory, are those made by the Winchester Repeating Arms Company — the regular front mounting and the No. 2 rear mounting. The front mount consists of a ring around the tube of the scope, and is secured to the barrel by means of a dovetail base and a screw. The tube bears on two convex surfaces placed 120 degrees apart inside the ring. In the bottom of the inside of the ring, and placed at 120 degrees from each of these convex surfaces, is a bevel-nosed plunger which engages in a long groove on the under side of the tube, and keeps the tube from rotating hut allows it to move longitudinally. This device insures the axis of the tube remaining constant, once it is adjusted.

Springfield rifle remodelled by A. O. Neidner, and fitted with Winchester telescope sight and Winchester mountings.

The shape of the rear mount is oval instead of circular, as in the case of the front mount, and is such as to allow ample play to the tube for elevation and windage adjustments for different ranges. Two springs, one exerting pressure vertically and the other horizontally, hold the tube in contact with the elevation and windage screws. The elevation and windage are set by micrometer screws reading to .001 inch. The division markings on the adjusting screws and mounts are enameled in red so as to make it easy to read them quickly and accurately. When the mountings are placed 7.2 inches apart one point of adjustment on either of the adjusting screws is equivalent to a change in point of impact at 100 yards of half an inch.

Small longitudinal dovetail bases are screwed to the barrel of the rifle the proper distance apart, and the bases of the mountings slip over these, being secured from slipping by thumb screws in the base of the mount. By loosening the thumb screws the mountings can be removed from the bases, thus removing the scope from the rifle, leaving only the small dovetail bases screwed to the barrel. Reference to the illustrations of the Winchester scope and mountings will make this description clear.

Views of Neidner .22-caliber Springfield magazine rifle, showing action and details of bolt. In this rifle the cartridge is not loaded into a holder, but is loaded direct from a .22-caliber magazine into a barrel regularly chambered for the .22-long rifle cartridge. The telescope sight is attached to the rifle with Winchester mountings and Mann taper dovetail bases.

The Winchester mountings as described are very satisfactory, in fact, almost ideal, in all respects save one. The method of attachment to the barrel is not altogether satisfactory, although in most cases it works very well. It is very necessary that some arrangement be had whereby the scope can readily be removed from the rifle, but this arrangement should be so positive and accurate that when the scope is removed it can be put back again and still be in absolutely accurate adjustment. Otherwise it will be necessary to sight the rifle in every time the scope is removed and replaced. Also the method of attachment should be absolutely rigid so as to allow no movement during firing, or from shot to shot. The Winchester method of attachment does not quite accomplish this, although it comes very near to it. Sometimes there will creep into the mounting an error of as much as two minutes of angle due to the lack of rigidness in this method of attachment. Either the retaining thumb screws become loose during firing, or the screws are sometimes screwed up tighter than at other times, thus causing a slight variation of the setting of the mounting on the base. Also the bases themselves, being secured to the barrel by screws alone, sometimes work loose under sharp recoil. Little trouble will be experienced, however, until we place the scope on a rifle of very sharp recoil, like the .30 caliber Model 1906.

A few years ago the late Dr. F. W. Mann invented a method of securing the mountings to the barrel. The mountings are so arranged as to fit on taper dovetails securely fastened to the barrel, by a driving fit which gets tighter instead of looser from recoil. The dovetail base is not only screwed, but also soldered on to the barrel so that it cannot possibly become loose. The base is dovetail in shape, and also tapers slightly from front to rear, the taper on both sides being at an equal angle with the axis of the bore. The under side of the mounting is cut out to fit over this base, and fits on it from the rear, the mounting sliding over the base, and wedging up on the taper to a positive fit. This gives fit which is absolutely secure, must come back to exactly the same place each time the mountings are removed and replaced, and which wedges tighter the more the recoil. Figs. 63 and 64 show the Mann taper dovetail base. A number of Winchester scope mountings have been altered by Mr. A. O. Neidner, the skilled riflemaker, so as to be secured to the barrel by means of the Mann taper dovetail bases, and these have proved perfect for the purpose, there being no error at all. In taking these mountings off the bases to remove the scope from the rifle it is necessary to drive them off with a piece of hard wood, using light, sharp blows, and to drive them on in the same manner. This may seem rather crude, but experience has shown that it is the only really satisfactory way if accuracy and absolutely positive results are to be secured. Before obtaining these taper dovetail mountings there was always an error in point of impact from day to day in my experimental work, sometimes amounting to as much as 2 minutes of angle, which I could not account for. With these mountings this error has entirely disappeared. For example, one day I would shoot a rifle in test at 100 yards and obtain a certain group with it, located at a certain point on the target. The next day I would make a similar test and would obtain another group about the same size as the first group, but perhaps as much as 2 inches away from the location of the first group, aim, sight adjustment, ammunition, everything exactly the same. This error was due to the error of the scope mounting, and the adoption of the Mann taper dovetail bases entirely removed this error.

The Mann taper dovetail method of attaching the telescope sight mounting to the barrel.

To test the mountings of a scope, the rifle should be firmly fixed in a very heavy vise where it will be absolutely immovable, and in such a manner that it can be aimed at a target at some distance off while thus immovably held. The target should preferably be at an even number of hundred yards. With the scope on the rifle, aim it at a spot on the target and screw the rifle up tight in the vise. Then remove the scope from the rifle without removing the rifle from the vise, place the scope back again on the rifle, and look through it at the target, noting whether the point of aim has moved in the slightest. If, after a half a dozen trials there has been no change in the point of aim on the target, the method of mounting the scope may be taken as positive and accurate. Place a mark on the target 10 inches above, and another 10 inches to the right of, the first aiming point. With the scope adjusted for the first aiming point, give the rear mounting additional elevation to move the point of impact up 10 inches. Look through the scope and see if it is now aimed at the upper mark. If so, the elevation adjustment is positive and accurate. Bring it back to aim at the original point, and adjust the mount to move the point of impact 10 inches to the right, look through the scope and see if it is now aimed at the right-hand mark, to prove the windage adjustment. With the scope aimed at the mark, move the eye from side to side a little through the lateral relief of the glass and see if the cross-hairs move on the target. If they do not, the cross-hairs are in focus and there is nothing the matter with the scope which would interfere with the accuracy. If they do move, then the cross-hairs should be carefully focused, moving them back and forth until they are perfectly distinct and yet moving the eye from side to side does not change the aim on the target. It is always well to repeat these tests with a scope every few months to see that everything is working all right. You are then sure that any error that may come up in the course of shooting is not an error of the aiming device.

The Winchester Style A, 5-Power Telescope Sight
This is the most modern and satisfactory scope manufactured in the United States. In fact it is the only one which the writer has found that is really satisfactory for use on a high-power rifle. Although by no means ideal it is a very good glass, and the best that can be obtained at the present time. The lenses are 3/4 inch in diameter, and the tube 15 7/8 inches long. The longitudinal relief is 2 inches and the latitude of longitudinal relief about 2 inches. The lateral relief is only about 1/8 inch, which is rather small, and trouble is at times had in holding the eye steady enough to keep the full field in view. This trouble is seldom experienced in target shooting but is at times rather aggravating in hunting. The eye-piece is of the terrestrial type, and is adjusted for focus by simply loosening the locking sleeve and turning the eye-piece until the proper focus is obtained, and then screwing up the locking sleeve. When the eye-piece is adjusted to suit the user’s sight, no further change should be made in it, focal adjustment for different ranges being obtained by adjusting the objective lens.

The micrometer adjustment of the objective lens provides a simple and accurate means for positive and minute relative adjustment of the lenses and cross-hairs required for accurate focusing of the image at the cross-hairs for various ranges. In using this micrometer focus adjustment always start at zero and screw the sleeve towards the rear. The following table shows the number of turns and divisions required to give perfect focus at the various ranges.

Winchester type A, 5-power telescope sight and mountings.

From 200 yards up, the focus of the objective lens is universal, and therefore requires no change in adjustment. For ordinary purposes the objective may be set in focus for 50 yards, and will answer very well for all distances from 25 yards up, but for constant use at any one range the objective lens should be carefully focused to avoid eye strain. In turning the micrometer screw to focus the objective lens, the lens itself does not turn but slides in the tube, being held from turning by a rib.

The cross-hairs are held in a reticule, and as opinions differ as to the best form of cross-hairs or other sighting points, five different styles of reticules are furnished; namely, single and double crosshairs, triangle, aperture, and post. The single cross-hairs are almost always to be preferred, except only for military target shooting at bull’s-eye targets, when the post is preferable, being shaped very similar to the front sight on the United States rifle, Model 1903, and aim being taken in the same manner, getting the post so superimposed on the image that the top of the post appears just below the bull’s-eye. These reticules are interchangeable, and one can be substituted for another without difficulty (see below).

The mountings for the Winchester scope have already been described. The tube glides through the mountings when the rifle recoils and has to be drawn back to a stop after each shot. This sliding of the scope is almost absolutely necessary. If it were rigidly fixed in the mountings it would receive too much of the force of recoil and would quickly become damaged. Also the tube sliding forward with recoil serves to carry the eye-piece away from the eye, so that there is no danger of the eye-piece striking the eye. If it were not for this sliding feature it would be necessary to have at least 5 inches longitudinal relief to a glass intended for use on a high-power rifle of heavy recoil, and this would materially reduce the size of field. The diameter of the field of this scope at 100 yards is 17 feet.

Directions for Removing Lenses from Winchester Telescope Sights
To secure the most satisfactory results from an instrument of this kind, it should be taken apart only when absolutely necessary.

Front or objective lens. Remove the adjusting sleeve cap. Unscrew the adjusting sleeve about 1/4 of an inch. Then return it to its original position. This leaves the rim of the lens cell exposed so that it can be pulled out. It is not advisable to remove the lenses from their seats in the cells, as they are liable to injury from improper seating.

Reticule (cross-hairs, etc.). Loosen the reticule retaining ring screw, situated on the left side of the tube near the rear end, by turning it inward as far as it will go, using the screw-driver furnished. The reticule holder may then be shaken out rearward by holding the tube vertically. If it sticks, rap the end of the tube gently on a smooth wood surface. After removing the reticule holder from the tube, the reticule disc, carrying the cross-hairs, or other form of reticule, may be removed through the slit provided for it. In replacing the reticule in its holder make sure the side on which the wires are soldered is toward the rear and the projection on the side of the disc is seated in its slot, so that when reassembled the reticule will stand upright.

Middle or inverter lens (style A or B, 5-power). Loosen the middle lens cell retaining ring screw, situated on the left side of the tube near the middle, by turning it inward as far as it will go. Then reach into the rear end of the tube with the finger or any hooked instrument and, engaging the notched end or the rear retaining rod, withdraw it with the rear diaphragm and middle lens cell attached. Replace in reverse order, making sure that when the retaining screw is tightened the center of its head is exactly in line with the line scratched across the slot in the tube.

The Winchester Style A, 5-power telescope sight is excellent for target shooting, particularly for Schuetzen rifles. I have had excellent results with it on a .30-40 Winchester single shot rifle. In fact I have used one of these glasses for over ten years, and have had it mounted at one time or another on over 20 rifles. It has always given perfect satisfaction except for the little trouble with the method of mounting on the barrel, as already noted, and the cross-hairs are so thick that it is difficult at times to get an absolutely accurate aim. The crosshairs should be made thinner. This glass has also been used by a number of our most skilled military rifle shots for long range shooting on the United States magazine rifle, Model 1903, with almost perfect results. The rifle can be used only as a single loader, and the scope must be pushed forward a little each time the bolt is pulled up so as to escape the bolt handle. On the 1903 rifle the mountings should be placed only 6 inches apart in order to give the rear mounting sufficient scope to permit of its adjustment to the extreme range of 1200 yards. When the mountings are placed 6 inches apart, one point adjustment on either elevation or windage screws moves the point of impact .6 inch for every hundred yards of range. On other rifles the mountings should be placed 7.2 inches apart, then one point of elevation or windage is equivalent to a change of point of impact of half an inch for every hundred yards of range.

It is always preferable to have the telescope mounted on the top of the barrel and as low down as possible, so that the eye-piece will come as nearly as possible to the same point that the eye-piece of a tang sight, like the Lyman, would come. Then one can take advantage of the- comb of the stock quickly to direct the eye into the line of sight, and can also press the cheek against the side of the stock, as he should, to hold the eye steadily in the line of sight If the scope be mounted on one side of the barrel in order to be able also to use the iron sights at the same time, or if compelled to do so because the rifle ejects its fired shells out of the top of the receiver, one must forego all this advantage of having the comb to direct the eye into the line of sight, and the cheek rest on the side of the stock. The eye bobs around in the line of sight, and it is very difficult to hold steadily. If necessary to mount the scope very high above the barrel, a cheek pad, made for use on shotguns, can be laced to the stock, thus raising the comb of the stock. For experimental firing the scope should always be mounted on top of the barrel, centrally over the axis of the bore. In fact I would advise that a telescope sight be not used on rifles that do not permit of its being so mounted, because the results are bound to be unsatisfactory, it being impossible to hold the rifle with any degree of steadiness when looking through the scope, except when shooting from a rest.

When it comes to a scope for all around use, target shooting, big game shooting, and military work, the Winchester scopes have many faults which makes them really unsuitable. Besides those already noted, the field is too small, the lateral relief is too small. The power should be less, about 3 power, and the lenses larger to permit a much larger and brighter field of view. The lenses should be more securely fastened in their cells against possible rotation. Greater longitudinal relief would be desirable. All these points, of course, were not fully appreciated when the Winchester scope was placed on the market.

The Ideal Telescope Sight
Throughout this chapter the various features of the scope have been discussed, the faults and the desirable features pointed out. If all these features were combined at their best in one glass we would have the ideal telescope sight. Thus our glass would be short and of rather larger diameter than the glasses now seen. The tube would be very strong so as to stand the hard knocks of real service. The lenses would be strongly secured in the tube against coming loose and also against rotating. The magnifying power should be about 3 diameters. The diameter of the field at 100 yards should be at least 30 feet. The longitudinal relief should be at least 3 1/2 inches, with a latitude of at least 3 inches. The lateral relief should be at least 1/4 inch. The field should be very bright, and without color fringe. Focus for clearness of vision and for distance should be arranged for exactly as in the Winchester scope. The mountings should be similar to the Winchester No. 2, and should be secured to the barrel by means of the Mann taper dovetail bases.

With such a scope the rifleman throws the rifle to his shoulder and instantly catches the aim. As his eye does not have to get exactly in the line of sight, as is the case with iron sights, he gets his aim much quicker with the ideal scope. The object is seen clearly magnified, and even brighter than when viewed with the naked eye. It is not necessary to get two sights into line, but only to move one sight, the cross-hairs, so as to have them superimpose on the magnified image. When the target is clearly seen it is much easier to get a quick aim at it than when it is indistinct. Every military rifleman knows how much quicker he can sight on a well-lighted bull’s-eye target than he can on a drab-colored silhouette. As the target is magnified, and the cross-hairs are thin, much more accurate aim can be taken than with coarse iron sights. In fact the ideal scope is a very much better aiming instrument than any other form of sight under all conditions. Its only disadvantage is that it is a delicate instrument, set up on top of the rifle where it is liable to damage by a fall, or by catching in limbs of trees, etc. This liability to damage can hardly be eliminated except by placing a heavy metal cover over the instrument, which would greatly increase the weight of the rifle.

Targets for Telescope Sighted Rifles
The conventional bull’s-eye target is not very satisfactory for use with the scope. It is difficult to aim accurately at the center of the large magnified black bull’s-eye as the black cross-hairs blend with the black of the bull and are not clearly defined. Particularly if the shooting is to be of an experimental character, or if it is to be a test of rifle or ammunition, it is much better to use a specially prepared target consisting of a bull’s-eye with a large white center. For this use, with the coarse cross-hairs of the Winchester type A, 5-power scope, I have standardized on a 100-yard target having a 6-inch black bull’s-eye with a 4-inch white bull inside it. This is easiest made with the materials at hand anywhere by using a compass, and drawing two circles on the paper target, one circle 4 inches in diameter, and the other 6 inches in diameter. Then take a small water-color paint brush, and with ink paint the space between the two lines, making a ring an inch in diameter. For other ranges use circles proportionately larger or smaller. The cross-hairs are then made to intersect on the white bull’s-eye inside the black circle, and the eye can do this with almost absolute accuracy.