The invention relates to a long recoil self-loading gun comprising: a barrel which can be moved against spring force from a position ready to fire to a drawn back (rearward) position; connected to the barrel a rotating bolt lock provided with a recoil spring; a firing pin; a receiver for guiding these elements; a magazine and a magazine holder fastened to the receiver; a stock formed from the receiver; and a loading opening as well as an ejecting opening formed on the receiver.

Generally, the long recoil gun means that the length of the recoil is one and a half times greater than that of the cartridge case. However, in most cases, for practical purposes much greater recoil is required.

The working element of firearms that use the energy of the gas generated by the burning gunpowder is the barrel. Due to the pressure of the gunpowder gases the bullet accelerates in the bore-hole of the barrel. In case of a certain quality cartridge and cartridge gauge considering a given bore-hole quality the muzzle velocity of the bullet - with which beyond the muzzle of the barrel it also leaves the zone of gas after-effects - is basically determined by the cartridge guiding length of the barrel. Preferably, this length in case of a rifled barrel is the length of its rifled portion. It is easy to see that a longer rifled portion of the barrel results in higher muzzle velocity and also higher muzzle energy, of course within reasonable limits determined by internal ballistic characteristics and production technology. In case of a given bullet the higher muzzle energy improves external ballistic and target ballistic characteristics, eventually the chance to hit the target. Besides the barrel all the other component parts of the firearm are merely used for ensuring undisturbed internal ballistics and a result of this for directing the bullet on a ballistic curve to hit the target.

Naturally, the length of the barrel in case of a conventionally constructed gun significantly determines the total length of the gun, that is, a very long barrel will produce a very long gun. Carrying, handling of a very long gun involves significant, often unacceptable compromises (e.g. moving is obstructed in closed quarters).

A conventional gun - in the operation system related to the invention as well - starting from the muzzle consists of the following component parts one after the other or overlapping each other: riffled barrel with the cartridge chamber, a locking mechanism for sealing the cartridge chamber and a resetting slide mechanism, the receiver accommodating the last two, the magazine and its adapter, the firing mechanism and apparatus as well as the stock. This kind of construction met the ergonomic requirements of human body through several centuries and it was suitable for riflemen moving slowly on foot in the open country. However, this construction implies spaces that can be considered as dead space in terms of energy conversion. Therefore the ideal case would be if the gun was not longer than the barrel. This, however, is required because of the compact seal of the barrel. Other, e.g. ergonomic and technical reasons also make it unrealizable. It is easy to see that handling of a gun greatly depends on the length of it. Consequently it is necessary to find an optimal ratio between the length of it and the length of the barrel.

The percentage between the length of the barrel and the total length of the gun, the utilization degree (rjkf) of the gun mechanism is the numeric value which shows the relation between the length doing the effective work and the total length of the gun mechanism. This ratio never can be 100%. In case of a conventional rifle this value is not more than 60%.

An optimized solution in case of guns (semi-automatic, automatic shotguns and rifles) is the so called Bull-pup design where the magazine housing including the magazine is placed behind the trigger mechanism and apparatus. With this solution the r) _kf value could be increased even up to 73%. However, in case of guns requiring great muzzle energy (typically in case of rifles with greater calibre) it is a necessary but not sufficient technical solution.

In case of large gauge size rifle designs the length of the barrel is significantly shortened which is a much worse technical solution. For a given cartridge the optimal barrel length (rifled barrel length) which can utilize the maximal energetic features of the cartridge is determined during the design of the cartridge. For a half inch (12.7 or .50) gauge size gun this length is always more than 1000 mm. Moving with such a long barrelled gun especially in closed quarters or transporting it in closed military vehicles is very cumbersome, in many cases it is impossible. Giving up the requirement for the maximal muzzle energy gun designers shortened the length of the barrel by 35% or more (as a result of which the muzzle energy was decreased at least by 10%). However, the total gun mechanism was still one and a half metres long. With the Bull-pup technical solution the n, _kf value was improved up to 64%.

The aim of the present invention is to decrease the length of the long recoil self-loading guns significantly for transportation while the length of the barrel is not changed. Thereby moving with the gun under any circumstances and hiding it in case of special defensive tasks become easier. A further aim is to make the long recoil self-loading gun carried with decreased length (here also standby state) ready to fire immediately, without requiring any assembling process.

It has been realized that the length of the gun during moving, carrying and transport does not necessarily have to be the same as during firing. Dismantling the gun into several pieces can be a solution but this is not the object of the present invention. To make the gun ready to fire in this manner is complicated and time-consuming after which the magazine must be inserted and the gun must be loaded too.

To solve this problem the present invention provides a gun according to the preamble which is provided with a clamp adapted for fixing the barrel in its rearward position which can be released by means of a release button.

In a preferred embodiment of the invention the movement of the barrel is guided between two points where the rear guide is ensured by the breech coupled to a linear guide-path, the front guide is ensured by a guiding element mounted in the receiver. At the end of the barrel being near the muzzle an arrester is placed which knocks against the receiver. At the front of the receiver or on a frame connected to the forepart of the receiver a clamp is provided which can be connected to the arrester by means of a releasable bolt the end of which is provided with a release button.

These component parts, solutions make carrying and transport of the gun in its short length state possible and enable immediate firing.

According to the solution of the present invention the length of the. gun to be carried (transported) can be shortened significantly, for example in case of a12.7 gauge Bull-pup type gun having a 730 mm long barrel this length can be decreased from 1 126 mm (rj _kf =64.9%) to 915 mm (rj _kf =79.8% which is unique in the world) while the gun does not have to be assembled for changing its length. An exemplary embodiment of the invention will be described with reference to the accompanying drawings in which:

Figure 1 shows the side-view of a possible embodiment of the gun according to the invention in its ready to fire state,

Figure 2 shows the side-view of the gun of Figure 1 in a state for carrying

(for transport),

Figure 3 shows a possible embodiment of the barrel stopping mechanism in closed state as viewed from above,

Figure 4 shows the barrel stopping mechanism of Figure 3 in open state as viewed from above,

Figure 5 shows the cross-section of the closed barrel stopping mechanism taken along line A-A of Figure 3 as viewed from the side,

Figure 6 shows the cross-section of the open barrel stopping mechanism taken along line B-B of Figure 4 as viewed from the side, and

Figure 7 shows the locking mechanism applicable for use in the exemplary embodiment of the gun according to the invention.

Figure 1 shows the technical solution of the long recoil self-loading gun according to the invention when it is ready to use that is ready to fire. In Figure 2 the same gun can be seen in a state when it is carried. The end point of the long recoil is limited by arrester 2 for example a disc fixed to barrel 1 so that arrester 2 knocks against the end surface 5 of front covering 4 of receiver 3. Arrester 2 advantageously engages with clamp 6 fixed to front covering 4 of receiver 3 and can be disengaged with a quick movement. At the user's wish barrel 1 and the locking mechanism fixedly coupled to it can be pushed back by hand against barrel 1 resetting and lock resetting spring till arrester 2 of barrel 1 impacts against end surface 5. Then in front of the flange of arrester 2 the nose-piece of the clamp 6 can be pushed down and it remains there by means of a bolt. At the endpoint of the backward movement the locking mechanism gets caught by its stopper and stays there while barrel 1 moves forward due to the force of its resetting spring, but the flange of arrester 2 immediately gets caught by the hooked nose-piece of clamp 6 thereby barrel 1 is fixed in its rear position. In this manner barrel 1 can be moved from its ready to fire state to a drawn back state and can be fixed in this position resulting in a difference ΔΙ_ between length L and L' where L is the length of the gun when it is ready to fire and L' is the length of the gun when it is transported (carried).This means a significant advantage for example during military use when the gun is carried by a person especially when getting in or out of a vehicle.

When clamp 6 is in released state arrester 2 freely passes under the hooked nose-piece of clamp 6. Then due to the energy stored in the resetting spring barrel 1 moves forward while the fired cartridge case is ejected.. When barrel 1 reaches its forward position the stopper of the locking mechanism is released thereby the locking mechanism also moves forward while a new cartridge is loaded in the cartridge chamber of barrel 1 and reliably closes the breech. The same process is enabled by releasing clamp 6.

Typically, in case of high performance long recoil guns using rotating bolt lock is expedient, but other known locking mechanism is also feasible.

The hammer trigger mechanism chosen suitably for this invention is already in stretched state during the common rearward movement of barrel 1 and the locking mechanism (the hammer spring stores energy as it is compressed) and remains in this state even during separate forward movement of barrel 1 and the locking mechanism. In this manner after closing the breech the gun is immediately ready to fire, only the trigger must be pulled for releasing the hammer so that by means of the energy stored in the hammer spring the firing pin could strike the primer.

Figures 3 and 4 show a preferred embodiment of the barrel stopping mechanism according to the invention as viewed from above. The barrel stopping mechanism can be switched between closed and open state by means of a bolt. Figures 5 and 6 show the sectional side-view of the barrel stopping mechanism in closed and open state. Clamp 6 is attached to the front covering 4 of receiver 3 through the fixedly mounted frame 7. It is to be noted that clamp 6 can be provided not only at the front of receiver 3, it may be placed on frame 7 coupled to the front covering 4 for example by means of a screw or a clip. In a certain embodiment frame 7 may be provided with a bipod made integral with it.

In order to securely fix arrester 2 onto barrel 1 an arrester body 13 may be used which can be screwed on barrel 1. This is shown in Figures 4 and 6. Barrel grab-hook 1 1 is held in open position by means of energy storing element 10. Advantageously, energy storing element 10 is a coil spring. Then another energy storing element 9 constantly stresses a bolt 8 in one direction the end flange of which knocks against the side of clamp 6. In this situation the flange of arrester 2 can pass unhindered under the hooked nose-piece of clamp 6. After barrel 1 is forced - against its resetting spring - to its rearward position, the barrel grab-hook 1 1 of clamp 6 can be pushed down against energy storing element 10. Then due to the energy stored in energy storing element 9 bolt 8 moves so that it keeps barrel grab-hook 1 1 closed. At this time the hooked nose of the barrel grab- hook 1 1 gets below the flange of arrester 2. In this manner forward movement of barrel 1 is prevented by means of arrester 2 securely fixed onto barrel 1. That is, barrel 1 is reliably fixed in its rearward position since the hook is not able to move upwards (opening direction) due to the form-fitting lock.

When bolt 8 is released by applying suitably chosen force F (in a direction indicated by an arrow in Figures 3 and 4) barrel 1 freely slides forward as the bolt releases the end of barrel grab-hook 1 1 and due to the energy released from energy storing element 10 it gets in a higher position than the flange of arrester 2 and the process of ejection and/or loading takes place. Because of the cocked hammer the gun is immediately ready to fire. After accurate aiming the gun can be fired. This solution is advantageous for example during shooting from the hip or when the gun is provided with an electro-optical sighting device.

Figure 7 shows the locking mechanism and the functional supplementary component parts applicable for use in the exemplary embodiment of the gun according to the invention. Locking mechanism 17 is provided with a rotating bolt lock head which is connected to breech 15 by a bolt. Housing of the resetting mechanism 20 is also a part of the locking mechanism 17. According to the present embodiment the lock resetting mechanism 18 moves in the housing of the resetting mechanism 20. In the housing of the resetting mechanism 20, at the end of it being near the forepart of the gun a lock stopper 21 provided with a spring is placed in the front groove of the housing of the resetting mechanism 20. Lock stopper 21 ensures the rear position of locking mechanism 17.When locking mechanism 17 reaches its rear position (right side in Figure 7) the lock head of locking mechanism 17 and breech 15 become unconnected by means of the wedge paths 19. These are commonly guided by means of a linear guide-path 14 which is fixed to the receiver. Though front guide 16 is independent from the elements explained in relation to Figure 7, it is still shown in the Figure since it serves for direction control during the whole recoil process of the barrel (not shown in this Figure). Front guide 16 may be made in one piece or several pieces, advantageously from bronze or a similar wear-resistant material having similar sliding properties.

In one embodiment the firing pin is blocked when the locking mechanism 17 provided with a rotating bolt is in open state.

A preferable exemplary embodiment of the gun according to the invention has been described. Naturally, this solution can also be used advantageously with other long recoil shotguns.