Gun with radial guides. Additional justifications of the concept
1. Preamble
Readers of the Military Review are probably familiar with the two previous articles: “The concept of a pistol. A look from a new perspective "and" Russian arc against stereotypes ", which talk about a conceptually new principle of a pistol device - radial guides (RN) of the shutter, which sets out the technical side of the issue, draws parallels with existing close analogues, confirms the feasibility of the idea, and also discloses a whole list of significant advantages achieved over pistols of the classical scheme.
However, despite the publication of articles and the arguments given in them, disputes over a new concept that offers a very paradoxical breakthrough solution continue, opinions are divided.
A number of reputable gunsmiths at various times supported the idea and showed interest in developing the topic. Among other things, a positive opinion was given by the specialists of ZiD JSC, Kovrov; a specific intention to engage in the development and production of a pistol was expressed by "TEKHKRIM"; “The Kalashnikov Concern in the last conclusion noted “that there are indeed a number of positive aspects in this scheme,” and others.
But, unfortunately, every time attempts to create a prototype of a conceptually new domestic pistol encounter all sorts of obstacles.
On the other hand, even such seemingly experienced specialists as the editor-in-chief of the Kalashnikov magazine Mikhail Degtyarev and his editorial staff, who have an education and work experience in the specialty "small weaponare strongly opposed to this idea.
In this they rely, among other things, on the negative conclusions of TSNIITOCHMASH.
The well-known gunsmith and blogger Konstantin Konev also repeatedly expressed doubts about radial guides, preferring broken guides.
There are also a lot of those who also claim about the supposedly “low-tech manufacturing” of the launch vehicle, which gives them people who are inexperienced in matters of production and are not even familiar with the capabilities of modern CNC technologies. Moreover, many readers are easily led to such “authoritative expert opinions” about the next domestic “no analogues”.
All this led to the need to write an article outlining additional, if possible, exhaustive explanations on the principle of RH.
It should be noted that TSNIITOCHMASH, in its official conclusions, does not question the feasibility of a LV pistol.
Here is an excerpt from the conclusion of 9.08.2022/XNUMX/XNUMX:
Note. These pistols with radial bolt movement (backward and downward) have been discussed in previous articles. Moreover, the radius of movement of the shutter in the Hamilton pistol is more than 10 times steeper than in the proposed pistol - 130 mm versus 1 mm, which leads to increased friction in the system and is significantly inferior to the proposed PH scheme. And yet the Hamilton pistol have worked!
But the obvious advantages of applying the PH principle, even such as reducing the height of weapons 20 mm or more while ensuring a full grip of the handle with all fingers (!); recoil arm 0 mm and "sporty" ergonomics, as well as self-cocking USM striker type and the minimum achievable thickness of the weapon 25 ... 26 mm at gate thickness 23 ... 24 mm – TSNIITOCHMASH does not consider them “of interest” and “with commercial potential”.
That is, the difference in height between the compact versions of the pistol with LV and the Glock-19 pistol is 107 mm versus 128 mm (!), according to experts, insignificant?
Below is their final opinion. Moreover, underlined in blue are claims that are determined only by the ammunition used and are not related to the design of the pistol. The remaining statements are also controversial, and they can be judged, at least only after testing a prototype.
Leaving the reader the right to decide for himself the question of the advantages and objectivity of the expert assessment of Klimov gunsmiths, let's move on to the main goal of the article - we will explain the essence of the principle as simply as possible.
2. Additional explanations
Analysis of a circuit with polygonal guides (LN)
On fig. 1 shows the well-known scheme of the KhRB-88 sports small-caliber pistol with broken guides (there are some conventions and assumptions).
Rice. 1. Gun with broken rails
Despite the fact that the scheme has been tested for decades, when switching to more serious calibers, a number of its serious shortcomings are revealed.
Rice. 2. The appearance of a gap between the frame and the shutter and shock processes during rollback
Let us consider the most realistic variant of the LN, shown in Fig. 1, with rear frame guides made on the butt plate of the handle (Fig. 1 b. and 1 c.).
Firstly, in the scheme with LN, when the shutter rolls back, a gap appears between it and the frame, see Fig. 2. Debris and foreign objects can enter this gap and become pinched, causing jamming and failure.
Rice. 3. The occurrence of misalignment and wedge clearance. Point contact in guides
Secondly, the factor of skew in the guides as the shutter rolls back causes the greatest doubts, see fig. 3, fragment A according to fig. 2 (enlarged).
The dark color here highlights the comb of the guides on the butt plate of the frame, which is included in the groove of the guides on the shutter, indicated in pink.
If we assume that when the shutter is in the forward position, its guides are parallel to the guides of the frame, then when the shutter moves backward, its rear part will rise along the inclined section of the guides, turning at a certain angle, and the parallelism between the guides will be violated.
On fig. 3 it can be seen that the dark rectangle of the ridge of the frame guides at the end of the shutter rollback is noticeably rotated and goes beyond the width of the groove of the guides on the shutter.
The misalignment in the guides makes it necessary to make guide frames either with beveled working surfaces, according to fig. 3, or in the form of a rhombus, "lentil", etc., and short in length. However, the wedge gap that will occur in this case is guaranteed to lead to jamming in conditions of pollution, since the principle of self-cleaning from dirt will be violated.
Also, since significant shock loads will occur in the guides at the time of the shot, in order to compensate for them, it is necessary to increase the section of the guides. And this, in turn, will lead to an increase in the thickness of the shutter, which is at least suboptimal, since it worsens the convenience of concealed carrying of a pistol.
In addition, the survivability of the guides is questionable, since the contact between them as a whole will pinpointrather than over the entire surface.
In the front guides, the picture will be similar.
From the foregoing, the conclusion follows: the geometry of the broken guides is not satisfactory, the reliability of the pistol is not ensured.
An in-depth and lengthy search by the author for constructive solutions to these problems of LN did not give satisfactory results.
3. Scheme with radial guides
From the scheme with broken guides, let's move on to considering radial guides.
Rice. 4. Scheme with radial shutter guides
And here we come to the climax. It suddenly turns out that if we replace the polygonal guides with radial ones, all these problems disappear, as if by magic.
And the mechanics of the reloading process remains the same.
The contact of both the front and rear guides will be carried out over the entire surface, which means that the specific loads in them will decrease, the survivability will increase, shock loads will be eliminated, the gap between the frame and the bolt will disappear during rollback, the principle of self-cleaning from dirt will be observed, which will eliminate the possibility of jamming guides.
As a result, the operation of the guides becomes similar to the rectilinear guides of classic pistols, with the only difference being that the movement occurs along a gentle arc of a circle of large radius with a relatively small movement of the shutter compared to the radius of the arc (45 mm to 1 mm).
In higher mathematics, in engineering calculations, this case is well known, and movement along an arc in this case is equated to movement along a straight line (arc chord) with an accuracy sufficient for engineering calculations (An additional proof of this is the value of the "segment arrow" in paragraph 5 below.)
This statement can be considered theoretically substantiated proof of the validity of the RH principle.
Depending on the design of the designer, various designs of pistols can be created on the basis of the launch vehicle: with separate - front and rear pairs of guides, with the same or different lengths; external or internal coverage; with solid guides for the entire length of the pistol, or with guides from the middle part of the frame to the butt plate - in this respect, the launch vehicles open up new opportunities for creative search and movement forward.
With regard to the manufacturability of PH, radius milling on modern CNC machines does not cause any difficulties and can be performed in one pass and with high accuracy.
4. Approximation of the LN by an arc of radial guides
The optimal, most expedient approximation of broken guides by radial ones is performed according to the scheme according to Fig. 5.
Rice. 5. Optimal approximation of polygonal guides by radial
As you know, three points define a circle.
In our case, three points (marked with a cross in a circle) will be distributed as follows: the first - the front point - coincides, of course, with the front point of the LN on the front end of the frame from above; the second is separated from the first by the distance of the shutter stroke horizontally; the third is the rear point of the broken guides on the butt plate end.
With this scheme, the "segment arrow" (see Fig. 5) has a minimum value of the order of 0,15 ... movement of the front end of the shutter in a straight line.
Rice. 6. Scheme with radial guides. Shutter rollback
5. Scheme with inclined guides (HH)
To complete the picture, we will also include consideration of the principle of inclined guides (hereinafter NN) of the shutter fig. 7. A similar pistol in caliber 9x19 was designed and manufactured by a unique enthusiast from the USA, Randy Neroni, and showed its performance. This has been discussed in previous articles.
Rice. 7. Scheme with inclined shutter guides
Rice. 8. Scheme with inclined guides. The rise of the barrel when the shutter rolls back
In this scheme with HH, two issues are decisive: the constructive solution of the muzzle of the pistol and the supply of a cartridge from the magazine.
In a design variant of the Neroni pistol, the muzzle of the barrel passes through a hole in the front end of the bolt. When the bolt moves back, the barrel rises, as shown in Fig. 8.
Raising the barrel can reduce the reliability of feeding a cartridge into the chamber, which is questionable.
Recall that with radial guides, the reliability of the cartridge feed, on the contrary, increases - an almost direct cartridge feed into the chamber is achieved.
To eliminate the rise of the barrel, a second version of the design of the muzzle of the pistol is possible. The muzzle of the barrel with a short stroke can move longitudinally in the hole of the bracket, vertically mounted in front of the pistol frame, or be mounted on a swinging vertical earring like a Browning earring. The front end of the shutter is open.
The disadvantages of this option are some bulkiness of the front of the pistol, excessive design complexity and a decrease in the length of the return spring, which can cause difficulties in creating shortened versions of the pistol.
Conclusion: with the same achieved advantages of the gun, radial guides are preferable to inclined ones.
6. Заключение
This article analyzes the broken, inclined and radial guides of the gun, the use of which can provide significant advantages over the pistols of the classical scheme, their distinctive features are shown, and the main disadvantages are noted.
The advantages of radial guides over broken and inclined ones are substantiated.
The logical expediency and advantages of the transition from polygonal guides to radial ones by means of LN approximation are disclosed and a scheme of their optimal approximation is given.
I hope theoretical proof consistency of the principle of radial guides.
PS
Additional information and videos are available in previous articles and on page VK author.
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