Comparison Gamo 3-9X40 AO vs Gamo 3-9X40 WR

The possibility of manual adjustment of the sight from parallax, by the user himself. For this purpose, the design provides a corresponding regulator.

Parallax in this case is a phenomenon when, when the eye deviates from the optical axis of the sight (from the center of the eyepiece), the aiming mark visible to the shooter also shifts, while the sight itself remains motionless. As a result, if the eye is not exactly in the center, the visible position of the mark does not coincide with the actual aiming point. This phenomenon is especially pronounced in optical sights (see "Type"), and many collimators are also subject to it, although not to the same extent (but "night vision" and thermal imagers are free of this drawback, since the mark is displayed on the built-in display).

To eliminate this phenomenon, a specific adjustment is used - parallax adjustment. It is usually done right at the factory. However, the sight can be adjusted from parallax only for a certain distance, and with significant deviations from this distance (more than 30% downwards or 60% upwards), this effect begins to manifest itself again. It can be compensated for by an ideal insert ("eye strictly in the center"), but even for experienced shooters this can be difficult, especially when shooting standing, offhand and in other uncomfortable positions. In light of this, some models also provide manual parallax adjustment - a regulator that allows you...to set the adjustment distance at the user's discretion. In addition to the situations described above, this function will be especially useful for novice users, as well as for high-precision shooting at long distances.

Optical sights with parallax adjustment> can be equipped with a wide ring on the AO (Adjustable Objective) lens or a drum on the SF (Side Focusing) control unit, on which additional accessories for fine-tuning the focus in the form of wheels are installed.

The location of the reticle in the optical sight (see "Type").

Such a grid can be installed either in the first focal plane, FFP(roughly speaking, in the lens area), or in the second, SFP(in the eyepiece area). At the same time, for sights with a fixed magnification, the difference between these options is only in price, so they use only the simpler and cheaper SFP. But in models with multiplicity adjustment, this parameter directly affects the application features, and we will analyze this difference in more detail:

— In the 1st focal plane (FFP). The key advantage of reticles in the first focal plane is that their apparent size also changes in direct proportion with a change in magnification. In fact, this means that the angular dimensions of the individual mesh elements remain the same regardless of the set magnification. That is, for example, if a distance of 1 MRAD is claimed between two neighboring points, then it will be 1 MRAD in the entire range of multiplicity adjustment. This means that you can work with the grid for measuring distances and taking corrections according to the same rules, regardless of the selected degree of increase. Thus, FFP sights are much more convenient and easier to use than SFP. On the other hand, such models are noticeably more complex and expensive; and many hunting reticles — for example, a duplex or a classic cross (see "Reticle Type") — it makes...no sense at all to install in the first focal plane. In light of all this, this option is relatively rare and only in mid-range and top-level models designed for high-precision shooting.

— In the 2nd focal plane (SFP). The most common reticle placement option, including variable magnification sights. Such popularity is primarily due to the simplicity of design and low cost. However, the reverse side of these advantages are additional difficulties when using goniometric mesh elements. The fact is that in SFP sights, the apparent size of such elements remains unchanged when the magnification changes, which means that the dimensions of individual parts at different magnifications will correspond to different angles. More precisely, the angular dimensions in such systems change in inverse proportion to the multiplicity: for example, if at a multiplicity of 5x the distance between two adjacent points is 6 MOA, then at 15x it will decrease to 2 MOA. Thus, the “true” angular size indicated in the characteristics, the marking elements have only at a strictly defined multiplicity, in other cases, this size must be recalculated using special formulas. At the same time, it is worth noting that if the grid does not have special goniometric elements, then this disadvantage becomes practically irrelevant for it; examples are hunting nets of the "half-cross" type (traditional, not "stump") and "cross with a circle" (see "Net type").

The type of aiming mark (reticle) provided in the device. There are models for which several options are indicated at once: this implies the possibility of switching between them.

As for specific varieties, in collimators, all brands have a common specificity - they should provide the convenience of quick aiming at relatively short distances. But the reticles of optical and other similar sights can be divided into hunting and tactical (sniper) sights. The former are relatively simple and have a minimum of additional elements, as they are designed for short distances and relatively large targets; and the latter are designed for high-precision shooting, military and police use, and therefore must be supplemented with various elements for measuring angles and taking corrections on the go, including between shots.

Among the specific types of grids most popular in our time are the cross with divisions, BDC, duplex, cross, half-cross, cross with a dot, cross with a circle, herringbone, rangefinder, dot, circle with a dot and circle with 2 points. Here are th...e main features of each:

— Cross with divisions. One of the most popular types of "tactical" reticles used in optical sights. The key element is the crosshair, on the lines of which additional dots are applied. The distance between the points corresponds to a strictly defined angular size; initially it was 1 MRAD (1 "mil", hence the name), however, in modern sights, other values \u200b\u200bcan be found, they should be specified according to the instructions. In addition, such grids can differ in the number of points, the presence of thickening on the lines (as in the duplexes described below), etc. Be that as it may, such a grid is very convenient for estimating distances and making corrections on the fly, many professional shooters consider it almost ideal for high-precision shooting, including at long distances, besides, the original cross with divisions (Mil-Dot) is widely used by military and police snipers around the world.
We also note that there is also a collimator variety of "mildots" - in this case, the grid looks like a circle with a dot in the middle and several dots below it, with an interval of the same 1 MRAD. However, when using collimators, the real need for making vertical corrections rarely arises, and this option is not widely used.

- Duplex. Reticles for optical and night sights (see "Type"), which look like a classic crosshair with different line thicknesses: they are thin in the center, and noticeably thicker near the edges. The meaning of this combination is that thin lines do not “clutter up” the field of view at the aiming point, and thick lines remain visible even under adverse conditions (for example, at dusk) and allow you to aim at least approximately. In addition, the thickness of large lines and the distance between their edges can correspond to well-defined angles, which allows some of these sights to be used even as simple goniometers. However, these possibilities are very limited, and in general, "duplexes" are classic hunting nets.

- Half cross. Hunting net, the main elements of which are T-shaped. One of the varieties of semi-crosses - "German grid", it is also "stump" - consists of a vertical line from the edge to the center of the sight and two horizontal lines that do not reach it; the aiming point corresponds to the upper point of the central "stump", and the thickness of the lines and the distance between them can be specified in the documentation - this allows you to carry out the simplest measurements of angles. A more modern version of the half-cross is the crosshair, in which one line (from the center to the top edge) is much thinner than the rest, or even absent altogether.

- Dot. In its pure form, the dot is used exclusively in collimator sights (see "Type"). This is an extremely convenient option for such devices: there are no unnecessary details in the field of view of the shooter, only a mark that clearly shows exactly where the weapon is aimed - more is often not required when using collimators. The disadvantages of the dot in comparison with other marks in the sights of this type include less visibility, especially in bright ambient light. However, many sights allow you to set a fairly high brightness of the mark, and sometimes even increase its size, increasing visibility. Also note that for a point, the angular size can be specified, which can be useful for quick estimation of distances.
In addition, the dot can also be used in optical and night sights, but in such cases it is usually used as an addition to another scale - for example, it additionally highlights the intersection of lines in a semi-cross.

— Circle with a dot. Another type of marks, used in collimators as the main one, and in other types of sights - as an addition to a crosshair or other more traditional grid. However, the latter is rare, so let's focus on the first option. Compared to another popular "collimator" mark - a dot - the circle covers more visible space, however, it is very noticeable and often turns out to be more convenient when shooting offhand or sharply turning the weapon to the side. In addition, for both the circle and the dot, it often indicates the exact angular size, which gives extended (compared to the usual dot) possibilities for using the aiming mark as the simplest goniometric (rangefinding) scale.

- Circle with 2 dots. A variation of the circle with a point described on top, having a second, additional point - usually below the first, at a strictly defined angular distance from it. This expands the possibilities for using the sight as an impromptu rangefinder, and also allows you to "on the move" take an amendment when shooting at long distances - just aim at the second, lower point. However, such opportunities for collimators are extremely rarely required, so this option has not received much distribution either.

- Cross. Features of this type of brand depend on the type of sights in question - optical / night or collimator (see "Type"). In classical optics, a cross is the simplest crosshair of thin lines of the same thickness. Naturally, in terms of general specialization, such reticles are hunting, but they are also found in a fairly advanced variety of sights - sports models for benchrest (shooting from a machine gun at maximum range and accuracy). The convenience of the cross in such an application lies in the fact that the lines have a minimum thickness and practically do not block the view. In nightlights, this type of grid is usually one of several options available to choose from. But in collimators, the cross is in many ways similar to a circle with a dot - it is provided as one of the large, well-marked marks with a clearly defined angular size.

- Cross with a dot. A grid in the form of a crosshair of two lines (as a rule, quite thin), at the intersection of which a clearly visible point is applied. It is in this form, as a rule, that is used in collimator and other types of sights. In the first case, such a stamp is actually a slightly modified version of the usual cross (see on top). And in optics, the presence of a point allows you to additionally highlight the crosshairs, which is convenient in some situations; the general purpose of such sights is, of course, hunting.

- A cross with a circle. Stamp in the form of a cross, complemented by a circle. It can also be used in different types of sights and has its own specialization everywhere. In classical optics, such a grid usually has a hunting purpose, although there are also varieties with additional marks that expand the "tactical" functions. And even in the absence of such marks in the characteristics, the angular size of the circle is usually specified, which provides additional opportunities for impromptu measurement of distances. We also note that the cross itself can be both ordinary and duplex (see on top). The situation is similar in night sights, however, there a cross with a circle is usually only one of the available mark options. As for the collimators, they can use both a full-fledged crosshair in a circle, and a ring with “rays” protruding from it; in any case, such a mark is more noticeable than an ordinary cross.

— BDC. This reticle got its name from the English phrase Bullet Drop Compensation, which translates as “bullet drop compensation”. The BDC ballistic reticle allows for range correction based on the bullet's trajectory. It is calibrated for a specific ammunition and sharpened for quick aiming at various distances using the same type of bullets. Distance markers in a ballistic reticle are hash marks, circles, or dots. The main sign of their placement is that the vertical markings have different gaps, increasing towards the bottom. An additional distance scale is often placed in such grids on the "six" shoulder. In addition, the ammunition for which the reticle is calibrated is usually indicated (caliber, bullet weight, weight).

- Christmas tree. Informative reticle resembling a Christmas tree in its structure. Actually, this is where the name of this type of grid came from. Each array of dots on its "six o'clock" arm is longer than the previous one - the marks increase in width when viewed from top to bottom from the central crosshair. These markers are used to correct for wind drift, which is extremely important when conducting aimed fire at long distances. The most common herringbone reticle is found in hunting hybrids, tactical sights, and military rifle scopes.

- Rangefinder. This type includes all grids that do not belong to any of the types described on top and provide for special markings for measuring angles and distances. The specific design of such markings may be different, but the general principle of operation is the same everywhere: rangefinder marks allow you to determine the angular size of a visible object, and if the linear size of this object is known, you can easily estimate the distance to it (at least approximately). Each type of rangefinder reticle has its own rules for use.

The type of mount supplied with the scope.

For normal mounting on a weapon, this mount must match the type of seat for the scope. The most popular types of mounts nowadays are on the Weaver / Picatinny rail and on the dovetail ; branded latches are noticeably less common, and some sights are supplied without mounts at all — this allows you to choose the option at your discretion. Here is a detailed description of specific options:

— On the Weaver / Picatinny rail. Fastening on a standard bar (“rail”) Weaver or Picatinny rail. It is considered the Western standard for installing a weapon body kit, but nowadays it is widely used around the world. It is worth noting that these types of slats, although similar in design, are not the same. They both have a T-shaped profile and transverse slots that allow you to securely fix the installed accessory in the chosen place, but differ in the size and location of these slots: they are wider in Picatinny rails and have a standard distance between centers. In fact, this leads to the fact that accessories for Weaver rails can easily fit on Picatinny rails, but not vice versa. In addition, Picatinny is considered more of a military standard, and civilian weapons are equipped mainly with Weaver rails. Thus, most of the complete rail mounts found among modern sights are designed specifi...cally for the Weaver rail, as it is more common and universal. However, exceptions are possible, so this nuance needs to be specified separately.

— "Dovetail". The seat of this type has a cross-sectional view of an inverted trapezoid, and the mount provides protrusions on both sides, which, when the sight is installed, “cover” this trapezoid. This type of mount is found mainly in air and sporting rifles, as well as in hunting weapons of a classic design. In the latter case, this choice is also due to aesthetic considerations — these mounts look neater than the gear "rails" of Weaver and Picatinny rails.

— Firm. Various specific fastenings not related to the standards described above. Often they are made not just for the products of a particular brand, but also for strictly defined models of weapons; one of the characteristic examples is the original seat on the high-end "sniper" Blaser R93. Branded devices can have a rather original design — for example, in some collimators for shotguns, a plate is used that is fixed between the butt and the receiver. In general, due to limitations in application, such fasteners are usually provided not as the only option, but as one of the options, in addition to the bar and/or dovetail.

Separately, it is worth touching on situations where several types of mounts are indicated in the characteristics of the sight at once. Most often this means that this model is available in different configurations, but there are other, more specific options — the presence of several types of mounts in the kit at once, an adapter from one type to another, or even a universal retainer that is also compatible with Weaver / Picatinny rails, and with a dovetail. Such details in each case should be clarified separately.