GB2371104A - Recoil damper system - Google Patents

Abstract

A rifle, shotgun or the like with a stock 136 comprises a coil damper system 111 which comprises a substantially constant resistance or a damper, e.g. a linear deceleration damper 128 which is a self-compensating multi-port hydraulic damper 128. The system 111 comprises at least one linear roller bearing 118, 120 which comprises a plurality of linearly arranged sets of bearing balls. The system 111 comprises inhibiting means 152, 154 adapted to inhibit operation of the damper 128 and comprising spring means 152, 154. The latter comprise springs and the system is adapted for the springs 152, 154 to be readily interchangeable with springs 152, 154 of other stiffness. The system 111 comprises a member 110 adapted to transmit to the damper 128 a thrust to be damped by the damper 128 but not a tension. The system 111 comprises a force-transmitting member 110 which bears against, but is not fixed to, the damper 128. A method of improving shooting skill is described, which comprises use of such a rifle, shotgun or the like and progressively modifying the same. A method of modifying a rifle, shotgun or the like to improve shooting skill is described, which comprises progressively reducing the inhibiting effect of inhibiting means 152, 154 on operation of a recoil damper system 128 of the rifle, shotgun or the like.

Description

TITLE :"Recoil damper systems" FIELD OF THE INVENTION This invention relates mainly to shotguns, rifles and the like, i. e. hand-held guns having a stock. Although mainly single-shot guns are relevant, the invention may have application to SLR's (self-loading rifles), semi-automatic and automatic (machine) guns.

BACKGROUND The most disliked effect when firing a rifle or shotgun is the effect of recoil on the user.

This can cause loss of accuracy as the gun is pulled'off the target'when the trigger is squeezed in anticipation of the recoil. If the gun is forced to go completely off target major correction is necessary for a second shot or the target will be missed.

The physical effect of continued recoil on a shooter causes shoulder or inner arm bruising and damage to neck and shoulder joints. It will also contribute to the onset of, or aggravate, arthritic and rheumatic symptoms.

Sometimes as a defence against the shock and discomfort of recoil, the brain will set up a resistance to the pulling of the trigger resulting in a'flinch'or'finger lock'.

This causes a delay in pulling the trigger and therefore a missed target usually results.

The complete elimination of recoil is not possible as the gun cannot be too heavy to use or carry around and the cartridge or bullet has to be powerful enough for its given purpose.

A number of methods for recoil reduction are available and most give a very minor reduction in the recoil felt by the shooter. Some of the most effective methods rely on the gun recoiling against springs in different forms (so-called"spring-loaded

systems"). This seems to work when the backward travel of the gun is quite large, for example 12 mm to 25 mm. This large movement of the gun against the shoulder and face is quite off-putting and can cause erratic movement of the gun barrels when the shot is fired. This causes great difficulty in firing a quick and accurate second shot.

The general opinion amongst shooters is that the most acceptable and efficient recoil damping system available at the present time is a hydraulic shock absorber system which is a retro fit to the end of the stock, i. e. it is fitted to the stock to interpose between the stock and the user's shoulder. It does however, have a number of problems.

The system of this kind which is most widely used in the UK is made by Danuser Machine Company of 550 East Third Street, Fulton, Missouri 48024, USA, and has been in use for many years. It uses an adjustable damper (shock absorber) made by them under the trade name Counter Coil.

The basic design of this prior art system is very simple, and is now described with reference to Figure 1.

There are two cast and machined aluminium contoured plates 10,22 facing each other at a distance of about 12 mm apart.

Projecting from the underside of the top plate 10 (as seen in Figure 1), which is approximately 150 mm long and 55 mm wide, there are two shafts 12,14 about 6 mm diameter which are 80 mm to 100 mm apart about a centre point 16 on the 150 mm length. These shafts 12,14 are approximately 50 mm long and run through bushes 18,20 in the bottom plate 22.

The bottom plate 22 is dimensionally similar to the top plate 10 but on the centre lines 24, 26 of the shafts 12, 14 are fitted the bushes 18, 20 just mentioned. These bushes 18,20 are about 30 mm long to give as much alignment support to the shafts 12,14 as possible. Each bush 18,20 fits snugly to its shaft 12,14 so that there is more or preferably less sliding friction between them, depending upon lubricant, respective materials and so on.

In the centre of the bottom plate 22 is a hydraulic shock absorber unit 28. This is positioned centrally between the two shafts 12,14 and is permanently fixed to the bottom plate 22. The main body 30 of the shock absorber unit 28 is below the bottom plate 22 and only its piston rod 32 protrudes above the upper face 34 of the lower plate 22.

On assembly, the stock 36 (shown in dashed lines) of the gun (extension of 36, not shown) is hollowed out at 38 to accept all of the metalwork etc below the underside face 40 of the bottom plate 22, that is the shock absorber body 30, the protruding length of the bushes 18,20 and the surrounding aluminium support body 42 of this plate 22. This plate 22 is held onto the stock 36 by two wood screws 44, 46 (schematically indicated).

To fit the top plate 10, the two shafts 12,14 are pushed into the bushes 18,20 in the bottom plate 22. To stop the system involuntarily coming apart a grub screw 48 in the side of the top plate 10 is tightened onto the side of the shock absorber piston rod 32 which fits loosely into a counter-bored hole 50 in the top plate 10.

With the system 11 correctly assembled, the shock absorber piston 32 can be pushed in by about 12 mm at maximum load.

The two main problems with this system are as follows:

1. The action of the shock absorber damper unit 28 which is an adjustable unit having a single oil port. This unit can be prone to leakage (and therefore failure) due to design requirements because it has to be adjustable, because of having to cope with different sizes of ammunition and different shooters (who generally feel recoil differently).

The basis of operation of this unit is that a load is applied to the end of the piston rod with the main body being held still (relatively speaking), the piston rod is forced into the shock absorber body where a quantity of special oil is confined below the piston bead. The oil is then forced through an orifice allowing the piston to move slowly and evenly downwards into the shock absorber body.

The problem with this single orifice design lies in its changing resistance during recoil. It can be adjusted (by rotating the piston to move a tapered member to or from the orifice) to give a high load resistance (hard to push in) or a low load resistance (easy to push in). This in operation gives a hard starting resistance and soft finishing resistance or vice versa. Even for adjustments in between, the resistance cannot be made constant. Because the recoil on firing the gun takes place in a very short time spell, i. e. milliseconds, the recoil reduction felt by the shooter will not be as smooth or effective as ideally required. The ideal action would be constant resistance or linear deceleration.

2. The shafts and bushes system of location and operation is prone to jamming when the load applied is too far off-centre to the damper unit. Also, the accuracy in the fitting of this unit to the stock is critical to its operation as the shafts will lock up in the bushes quite easily. For example, very slight flexing of the bottom

plate due either temporarily to an off-centre load or permanently to mounting to a non-flat portion of the stock, will cause the shafts to jam in the bushes.

When this fault occurs, the recoil shock is transmitted through the shafts and bushes, bypassing the shock absorber unit, and passing ultimately into the shooter's shoulder.

Thus, whilst this system provides some improvement over one having no hydraulic damper, it has disadvantages in that its action is not always smooth or consistent, it often binds up (so that there is little or no damping), it requires to be adjusted manually for any change in the size of the charge or ammunition, it needs to be re-set by trial and error for different users and for changes in the user's pressure holding the stock against the shoulder before shooting, it loses its effectiveness if the user presses the stock heavily and/or for a long time against the shoulder before shooting.

THE INVENTION The inventor tried out numerous adjustments to the prior art damper of Figure 1 and the system in general, which had been the best available for many years, trying to improve the operation, but without success. He then carried out extensive investigations to find out what problems were involved and analysed them. Part of his analysis is given above. The problems were, broadly speaking: firstly, the difficulties of providing smooth and preferably linear deceleration, coping with different loads, and larger loads, and making the stroke as short as possible; secondly, the persistent binding, which he analysed and found occurred both in the case of shooting upwards or downwards and in the case that the damping system was not

fitted accurately to a flat on the stock ; and thirdly, the loss of damping effect upon too high or too prolonged a pressure of the stock against the shoulder before shooting.

According to one aspect of the invention there is provided a recoil damper system as claimed in claim 1, preferably as claimed in claim 2.

From his special knowledge of the very different art of machine tools the inventor found out that what was required to help deal with the first set of problems was a self-compensating damper, and the one most convenient, and appropriate to the space and other requirements of this particular application, was a self-compensating multi-port hydraulic damper such as used for machine tools. Such a multi-port damper gives smoother deceleration during recoil and is substantially self-compensating for different sizes of shot.

According to another aspect of the invention, there is provided a recoil damper system comprising linear roller bearings. The rollers may simply be balls.

The inventor found that the second set of problems resulted in both cases from binding occurring in the bushes due to recoil forces being applied off-centre, i. e. somewhat obliquely to the axes of the bushes, these axes being parallel to the direction of movement of the damper. This was due in the one case to the changed position of the stock in relation to the shoulder when shooting upwards or downwards and in the other case to the flexing of the base plate of the system when fitted incorrectly to the stock. He realised, again from his knowledge of the art of machine tools, that a solution to the difficulties would be to employ, instead of bushes with sliding friction, roller bearings extending linearly in the direction of movement of the damper, i. e. co-axial with the axis of movement of the damper, since these bearings were well capable of coping with oblique forces. Such linear roller bearings stop the

damper from binding up when load is applied off-centre (such as shooting upwards or downwards).

According to another aspect of the invention, there is provided a recoil damper system comprising a damper and inhibiting means adapted to inhibit operation of the damper.

The inventor analysed the third set of problems as follows. The usual damper is adapted to damp sudden or high pressures (forces), e. g. 90 kilogrammes, such as upon recoil. It often cannot withstand low pressures slowly applied, such as a shooter pressing the stock, possibly hard, against his/her shoulder before shooting. The use of inhibiting means can inhibit operation of the damper in relation to slowly applied low pressures, e. g. about 10 to 20, or even to 40, pounds weight (4.5 to 9, or even to 18, kilogrammes weight) over a period of about 0.5 to 5 seconds. Thus, the damper system can be expected not to operate substantially, i. e. for more than about say 10% or 25% of its movement, for the expected pressure of the stock against the shoulder before shooting but to operate effectively for the much higher pressure due to recoil.

It may be preferable to be able to pre-set and/or vary the strength of the inhibitory effect. (Effectively, in practice, there may thus be considered to be a threshold above manual pressure but below pressures corresponding to recoil at which the inhibitory effect is overcome and the damper is able to operate. However, the threshold may be a soft threshold and not have a sharp, precise value. It may be possible to pre-set and/or vary the threshold. ) Suitable inhibiting means can be achieved most readily by spring means but other means are not excluded.

Back-pressure spring means for this purpose (a) can avoid the user depleting or exhausting the damping function before shooting (pulling the trigger), (b) can

comprise spring means and these can be replaced to substitute springs of different strengths of resistance/inhibition according to the pressure of stock to shoulder of different users, or of one user progressively, the system being adapted for the springs to be readily interchangeable with springs of other stiffness, and (c) can help the user to learn to use lighter pressure of stock to shoulder, using progressively lighter springs; which can facilitate more efficiency from the damper, and smoother shooting and greater accuracy.

Feature (c) is particularly suitable for people new to shooting, women and younger people (ages 12 plus), for all of whom the recoil would otherwise be startling and/or painful. With this embodiment, they readily learn to use lighter and lighter (until snug) pressure of stock to shoulder as they gain confidence.

According to another aspect of the invention, there is provided a recoil damper system comprising a member adapted to transmit to the damper a thrust to be damped by the damper but not tension, or at least not more than a predetermined amount of tension. It is suitable to use a force-transmitting member which bears against, but is not fixed to, the damper. This will be able to transmit thrust to the damper but not tension.

Use of a non-tension-transmitting member, or limited-tension-transmitting member, can have particular application in the case of use of the said springs, and will avoid the piston being pulled by them too strongly (or at all) and damaging the damper when it is able to return to its normal condition after recoil, but may also be used in other cases where strong tension could damage the damper.

The invention may have application to other cases where a sudden shock is to be smoothed out, e. g. with car bumpers, e. g. more particularly where the shock can be

applied off-centre, i. e. obliquely to the line of movement of the damper or at a point not on the centreline of the damper.

According to another aspect of the invention, there is provided a recoil damping system for a rifle, shotgun or the like, comprising two spaced apart plate-like members as between which there is a recoil damping effect, characterised in that at least the periphery of the space between the members is filled with a sponge-like material.

According to other aspects of the invention, there are provided: a rifle, shotgun or the like, characterised in that it comprises a system embodying the invention as described above; a method of improving shooting skill, characterised in that it comprises use of such a rifle, shotgun or the like and progressively modifying the same; a method of modifying a rifle, shotgun or the like to improve shooting skill, characterised in that it comprises progressively reducing the inhibiting effect of inhibiting means on operation of a recoil damper system of the rifle, shotgun or the like.

DESCRIPTION RELATING TO THE DRAWINGS Reference will now be made by way of example to the accompanying drawings, in which: Figure 1 is a side view of, in principle, the known Danuser system, viewed from its long side; and Figure 2 is a similar view of a damper system embodying the invention.

Corresponding items in Figures 1 and 2 have the same references except that those in Figure 2 have a prefix"1".

Referring to the drawings, the Danuser system has been described above with reference to Figure 1, though this Figure has some minor changes from the actual

Danuser system to allow a ready comparison with it of the invention embodiment shown in Figure 2. There are also differences in dimensions and proportions, not apparent from the respective Figures, between the Figure 2 embodiment of the invention and the Danuser system.

The main improvements are the shock absorber (damper) 128 itself which is of a different design from damper 28, and the use of linear bearings 118,120 for shafts 112,114 instead of bushes 18,20 for shafts 12,14. All this eliminates the lockup (binding) problem that occurred with the shafts 12,14 and gives a consistently very smooth movement.

The Figure 2 recoil damper system 111 comprises a substantially constant resistance or linear deceleration damper unit 128, which comprises a self-compensating multi-port hydraulic damper 128.

The shock absorber 128 used is a high efficiency design using a system of multiple metering orifices. It was obtained from Ace Controls International of POB 71, Farmington, Michigan 48024, USA, under their reference MC150 MH2. As the load is first applied, the piston (on rod 132, inside body 130) moves gently back creating an immediate pressure rise in the pressure chamber (not shown, inside body 130). The hydraulic oil behind the piston can initially escape through all of the metering orifices. The number of these orifices in action decreases proportionately to the distance travelled through the stroke, smoothly reducing the velocity of the moving load. The internal pressure and thus the reaction force (resistance) remain essentially constant through the complete stroke length providing a substantially constant deceleration rate which is substantially'true'linear deceleration. These

features allow the unit 128 to be self-compensating, so that it does not have to be adjusted for different sizes of ammunition and different shooters.

Because the unit 128 does not need to be adjusted in this way, the seals of unit 28 are here replaced by a single dynamic seal. This is known as a hermetically sealed rolling diaphragm seal, and unit 128 comes with a lifetime guarantee against leakage.

This unit 128 causes less recoil to be felt by the shooter than unit 28 with a single metering orifice.

Because these units 128 are so efficient in use they are capable of stopping a load of more than double that of a single orifice adjustable unit 28 that is a comparable shock absorber of the same size and weight. Another advantage of using this type of 'self-compensating unit'is that any range of different load types (cartridges) creating more or less recoil can be used-the linear deceleration will always be at its most efficient for that load.

The embodiment uses 8 mm diameter shafts 112,114, 47 mm long, which are 60 to 64 HRC (Hardness Rockwell Charlie). These are very hard carbon steel shafts hardened and polished to give long life and smooth operation. Instead of the bushes 18,20, the system 111 comprises what are called linear bearings 118,120, more properly called linear roller bearings 118,120 ; as used in this embodiment, these are more specifically linear ball bearings, and each bearing comprises a plurality of linearly arranged sets of bearing balls, the lines extending in the direction of compression of damper unit 128. The bearings used are obtained from Nippon Bearing Co Ltd of 2833 Chiya-Kou, Ojiya Niigata, 947-8503 Japan as"8 mm linear bearing, steel bush, resin retainer". These are made up of essentially eight parallel adjacent rows of tiny ball bearings (approx 1 mm diameter) which are held in position

in a resin liner which fits into a high-carbon steel outer body. The eight rows are divided into four pairs of adjacent rows, each pair being arranged as the long sides of a long narrow rectangle, the four rectangles being arranged side by side around the inside of the bearings 118,120, so that the rows extend in the direction of the length of the bearings 118,120. The dimensions of each bearing 118,120 are 16 mm DID (outside diameter), 8 mm lID (inside diameter), and they are 25 mm long. These bearings are specifically designed for coping with slightly misaligned shafts and are therefore ideally suited for use in the assembled system of the Figure 2 embodiment.

It is very important that the shafts 112,114 slide though the bearings 118,120 very smoothly or they will act as recoil transmitters from the gun to the shoulder by bypassing the recoil damper 128.

When the gun is mounted into the shoulder horizontally to the body, the load on the shafts is fairly equal and they can pass through the bushes relatively easily. When the gun is mounted into the shoulder to shoot down below the feet or up above the head, the load on firing the gun is transferred to either the'toe' (bottom) or the'heel' (top) of the stock. This action tends slightly to force the shafts 112,114 out of perfect alignment with the bearings of 118,120. With the prior system, this then caused the shafts 12,14 either to lock or 2 drag in the bushes 18,20, and in both instances more'felt'recoil was transmitted to the shoulder without passing through the shock absorber 28. This situation is remedied by using the linear bearings 118, 120.

The use of linear bearings 118,120 in this embodiment has also made the assembly of the system 111 onto the gun much easier, i. e. accuracy of flatness of

mounting to end of stock 136 is not so critical (which in the prior system, by causing flexing of plate 22, also caused binding).

On the Danuser unit, the level and flat fitting of the system 11 is critical. If the stock 36 is out of flat and level by just a few thousandths of an inch (hundredths of a mm) over its length that seats the system 11, 'lock up'on the shafts 12,14 can occur.

On the Figure 2 unit, whilst it is aesthetically desirable to have a good fit to the stock 136 of the gun, it is not necessary to have the same degree of accuracy in the fitting to ensure the smooth operation of the system 111. There is no practical situation known to the inventor where, on assembly to a stock, the system 111 would for this reason fail to operate correctly.

A disadvantage of using hydraulic dampers, particularly the self-compensating shock absorber, is that the piston is easily pushed into the body of the unit 30,130 when a light load is placed on the end of the piston rod 32,132. This situation occurs when the gun is mounted into the shoulder, pulled back into the shoulder and aimed at the target. To combat this, the system 111 comprises inhibiting means 152,154 adapted to inhibit operation of the damper 128. The inhibiting means 152,154 comprises spring means 152,154 in the form of two compression springs 152,154 placed between the two plates 110,122 and sited centrally between the shaft 112,114 and the piston rod 132. They are correctly located by means of recesses 156,156 in plate 110 and recesses 158,158 in plate 122. These create a resistance to the pulling back of the stock into the shoulder. This allows the gun to be mounted snugly into the shoulder whilst compressing the recoil damper 128 wholly 2 mm to 3 mm before the gun is fired. Ample space is left between the top and bottom plates 110,122 of

the system 111 for the recoil to be absorbed by the shock absorber 128 before the two plates 110, 122 touch. The total stroke of the piston rod 132 under recoil is about 10 mm, a reduction compared with the 12 mm needed by the prior unit 28 (and up to 25 mm for spring-loaded systems), permitted by the multi-port self-compensating design of unit 128. This allows the system 111 to be shallower than prior system 11 (the vertical direction as seen in the Figures), thus requiring much less reduction in the length of the stock 136 (to maintain the total stock length constant) when fitting the recoil damping system 111 to it than system 11 to stock 36.

As different people mount their guns into the shoulder with different force, the system 111 is adapted for the springs 152,154 to be readily interchangeable with springs of other stiffness. There are included with the system 111, as sold, three sets of springs 152,154-soft, medium and firm-which are interchangeable and can be fitted as required. In order to cope with shoulder pressures of 10 to 40 pounds weight (4.5 to 18 kilogrammes weight) the sets of springs 152,154 may conveniently be rated at a pressure (force) for total compression of 20,40 and 60 kilogrammes weight respectively. Under shoulder pressure, they will then only be compressed slightly. The recoil pressure with which the prior damper unit 28 is intended to cope is about 90 kilogrammes weight. Due to the improvements consequent upon the design of the self-compensating multi-port hydraulic shock absorber 128, this is able to cope with a recoil pressure of 200 kilogrammes weight.

Thus, the gun can be modified to improve shooting skill, by progressively reducing the inhibiting effect of inhibiting means 152,154 on operation of the recoil damper system 111 of the gun by successively using the firm, then medium, then soft

set of springs 152, 154. This provides a method of improving shooting skill, comprising use of the gun and progressively modifying the same.

As mentioned above, to mount the prior system 11 to stock 36, the latter is provided with a cutout 38, plate 22 carrying unit 28 and bushes 18,20 is then mounted to stock 36 by means of screws 44,46. Upper plate 10 carrying shafts 12, 14 is then located so that shafts 12,14 enter bushes 18,20 and recess 50 surrounds the end of rod 32. Then grub screw 48 threaded into plate 10 is tightened onto the end of rod 32 to hold plate 10 to rod 32 and hence to plate 22.

This last step is inappropriate with the Figure 2 embodiment. Instead, the free end of piston rod 132 must rest loosely in recess 150. Then, for the reasons explained above, upper plate 110 serves as a member 110 adapted to transmit to the damper 128 a thrust to be damped by the damper 128 but not a tension. This force-transmitting member 110 thus bears against, but is not fixed to, the damper 128.

In the case of the Figure 2 embodiment, in contrast, before mounting plate 122 to stock 136, plate 110 is held to plate 122 by means of a shoulder bolt 156, passing freely through plate 122 and conveniently passing through the centre of spring 154 and threaded only at its upper end where it engages upper plate 110. The shoulder 158 at the head end of bolt 156 holds captive plate 122 to plate 110, and the length of bolt 156 is chosen so that, when fully tightened into plate 110, it will keep springs 152, 154 in slight compression. The whole system 111 is then mounted to stock 136 by means of wood screws 144,146 rotated by means of a screwdriver inserted through holes 145,147 in upper plate 110. The whole of upper plate 110 is then covered by the usual shaped so-called"heel plate"164 which fits against the shooter's shoulder.

The aforesaid adaptation, for the springs 152, 154 to be readily interchangeable with springs of other stiffness, is then that system 111 can be dismantled by unscrewing bolt 156 to allow plates 110,122 to be taken apart and springs 152,154 to be interchanged with springs 152,154 of different stiffness.

In order to avoid trapping of clothes or skin between the plates 110,122 of the recoil damping system 111, comprising the two spaced apart plate-like members 110, 122 as between which there is the recoil damping effect, at least the periphery of the sheet-like space between the members 110,122 is filled with a sponge-like material 162 which can be readily compressed as the plates 110,122 approach one another during recoil, and preferably has the shape of a sheet 162 with cutouts to accommodate those items that have to pass through it. This also inhibits dirt from entering system 111.

It will be apparent to one skilled in the art, that features of the different embodiments disclosed herein may be omitted, selected, combined or exchanged and the invention is considered to extend to any new and inventive combination thus formed.

Claims (16)

1. CLAIMS 1. A recoil damper system for rifles, shotguns and the like, characterised in that it comprises a substantially constant resistance or linear deceleration damper.
2. 2. A system as claimed in claim 1, characterised in that the damper comprises a self-compensating multi-port hydraulic damper.
3. 3. A system as claimed in claim 1 or 2, characterised in that it comprises at least one linear roller bearing.
4. 4. A system as claimed in claim 3, characterised in that a said linear bearing comprises a plurality of linearly arranged sets of bearing balls.
5. 5. A system as claimed in any one of claims 1 to 4, characterised in that it comprises inhibiting means adapted to inhibit operation of the damper.
6. 6. A system as claimed in claim 5, characterised in that the inhibiting means comprise spring means.
7. 7. A system as claimed in claim 6, characterised in that the spring means comprise springs and the system is adapted for the springs to be readily interchangeable with springs of other stiffness.
8. 8. A system as claimed in any one of claims 1 to 7, characterised in that it comprises a member adapted to transmit to the damper a thrust to be damped by the damper but not a tension.
9. 9. A system as claimed in any one of claims 1 to 8, characterised in that it comprises a force-transmitting member which bears against, but is not fixed to, the damper.
10. 10. A recoil damper system for rifles, shotguns and the like, substantially according to any example hereinbefore described.
11. 11. A recoil damper system for rifles, shotguns and the like, substantially according to any example hereinbefore described with reference to the accompanying drawings, other than the prior art example described with reference to Figure 1.
12. 12. A recoil damper system for rifles, shotguns and the like, characterised in that it comprises linear roller bearings.
13. 13. A recoil damper system for rifles, shotguns and the like, characterised in that it comprises a damper and inhibiting means adapted to inhibit operation of the damper.
14. 14. A rifle, shotgun or the like, characterised in that it comprises a system as claimed in any one of claims 1 to 13.
15. 15. A method of improving shooting skill, characterised in that it comprises use of a rifle, shotgun or the like as claimed in claim 14 and progressively modifying the same.
16. 16. A method of modifying a rifle, shotgun or the like to improve shooting skill, characterised in that it comprises progressively reducing the inhibiting effect of inhibiting means on operation of a recoil damper system of the rifle, shotgun or the like.