DPM Systems Technologies Ltd.

Article in "STRZAL" (Poland)

Article written by Mr. Krzysztof Sudol & Mr. Hubert Giernakowski in "STRZAL" issue of October 2005

Evaluation of Magnetomechanical systems for recoil's reduction

Systems for recoil's restriction upon firing are not something new. A lot of companies manufacture those kinds of mechanisms for both long and short guns. These mechanism function with various standards and have different potency. In the present article we would like to present one of these, manufactured on the base of an interesting idea and intended for the Glock pistols.

The whole mechanism is constituted of two parts: of a magnetic plate and a system of 3 recoil springs, of which the work is the deceleration, in the last phase, of the speed of slide's regression upon firing. Absorbing the recoil energy of gun, the system normalizes the slide's strike on the frame of gun and the perceptible for the user "kick". The advantages of the mechanism, reportedly of the constructor, are:

  • vitiation of felt recoil of gun
  • vitiation of bounce of gun
  • shorter harmonisation of shooting parts after the shot
  • protection of the frame
  • shorter and better accurate second shot (double tap)
  • easy and fast assembly of mechanism.

The central recoil spring (5, drawing 2) functions in a steely, cylindrical axis of control (rod) (1), and is supported on the one hand of the front side of the slide (K) and on the other hand in wall of mechanism of control (T). The second and smaller spring (2) with his axis of control (4), is fixed inside the rod (1), suchwise as it appears in the drawing, and leads to base (7), which is supported in the body of barrel. In the front part of rod (B) is also placed a spring (3), secured with a cap. The set is completed of a flat magnet (M), situated at the front surface of the slide, applied in the frame of gun Piccatiny (9).

In disposal state for the shot the springs 2 and 5 work with small strength, as result of the mechanism's effect in slide. Spring 3 remains free in chamber B, without any initial pressure. Magnet (M) abuts on the front surface the slide and also on the edge of the rod (1), which ends on a metallic cap (6). Upon firing, the increasing pressure of gunpowder's gases which affects the slide (K) causes regression, facing the force of magnet (M) and begins the compaction of spring (5) at its backwards movement. At the same time, the strength of spring (2) - considerably bigger than the spring (5) - and the attractive power of magnet (M) maintain the cylinder (1) in his initial place, keeping it from moving back. Then, the slide, receding reaches in the `' flange `' (S) of the cylinder (1). At this point the slide recedes with cylinder (1), and the spring (5) is completely compressed. The slide, the spring (5) and the cylinder (1) recede as indiscrete body, pressing the spring (2). Before the wall of the cylinder (T) touch the base of mechanism of control (7), the slide and the cylinder, that recede more and more slow, meet the resistance of spring (3) in chamber (B), which "stops" its back movement. Under the effect of compressed springs (2) and (5), all the body: slide - cylinder begins now the front movement, closing the slide and locking again the barrel.

The whole mechanism functions also without magnet (M). Its role is limited in the deceleration for a flash of slide's opening and barrel's opening, increasing by this way the biggest pressure of gases of gunpowder in the barrel. At the Constructor's claims, this increase causes little bigger initial speed of bullet, as well as changes the gunshot. The constructor proposes two types of spring (5): in golden colour with force 3,75 kG as well as in silver colour, with force 4 kG, is recommend the application of the first with the magnet, and of the most powerful - without magnet. Both two springs can be applied in various compositions of system, alternative, at the estimation of user.

For the verification and the evaluation of operation of magnetic - mechanic system of recoil's reduction of gun, we decided to run some simple tests in the shooting range. First of all, we wanted to verify the aspect for the effect of magnet at the moment of slide's opening and, consequently, for the increase of initial speed of bullet. For that reason we have measured the initial speed of two kind of munitions "full metal jacket", shot with the pistol Glock 17, with conventional recoil spring, as well as with placed magnetic - mechanic system with spring 4 kG. For the tests we used munitions with bullets of mass 124 gr (8 g) by Magtech company and also with bullets 115 gr (7,.5 g) by Sellier and Bellot company. We measured the speed of bullets with the Master Chrony chronoscope.

1. We have not realised the effect of magnetic part of mechanism in the initial speed of bullet, for both mass 115 and 124 grain. 2. According to expected, the on average speed of lightest munitions was bigger in both cases. Results in the following table:

  Speed in  m / s Speed in  m / s  
Standard spring 321,2 342,9 Standard spring
Munitions 124 gr 338,2  358,5 Munitions 115 gr
  339,1 362,7  
M.O. 336,62  m/s 332,3 361,2 M.O. 357,32 m / s
  337,3 361,3  
Magn/chanical Syst. 335,5 349,6 Magn/chanical Syst.
Munitions 124 gr 331,0 360,0 Munitions  115 gr
  331,5 347,9  
M.O. 332,36  m/s 348,1 366,6 M.O. 357,64 m / s
  315,7 364,1  



  Time in sec Time in sec  
Standard spring 0,26 0,20 Standard spring
Munitions 124 gr 0,22 0,39 Munitions 115 gr
  0,22 0,39  
M.O. 0,23 sec 0,25 0,42 M.O. 0,35 sec
Magn/chanical Syst. 0,20 0,19 Magn/chanical Syst.
Munitions 124 gr 0,18 0,17 Munitions 115 gr
M.O. 0,22  sec 
0,22 0,20 M.O.  0,18  sec



  Time in sec Time in sec  
Standard spring 0,43 0,49 Standard spring
Munitions 124 gr 0,38 0,47 Munitions 115 gr
  0,39 0,44  
M.O. 0,40 sec 0,40 0,45 M.O. 0,46 sec
  0,49 0,33  
Magn/chanical Syst. 0,35 0,36 Magn/chanical Syst.
Munitions 124 gr 0,42 0,37 Munitions 115 gr
M.O. 0,39  sec 
0,37 0,34 M.O.  0,34  sec
  0,34 0,31  


The second part of test came for the measurement of time of two fast continuous shots to conventional target IPSC from distance of 5 metres. The shooters should get the central field Alpha. The test came with 2 shooters. The first should have shot two fast shots without have targeted (duble tap or dublet) and the second should also shot two fast shots, but under control of foresights (that is to say controlled pair). The test was carried out also with the two pre-mentioned kind of munitions. The results of tests are in the above table.


1. The magnetic - mechanic system accelerates the implementation of two fast shots double tap and control pair as well, but mainly with lighter munitions.
2. With munitions 124 grain this difference is small and appears without practical importance.
3. At the gunfire with lighter munitions, the profits from the tested mechanism are very obvious.
4. By the occasion, it appeared that upon firing with conventional recoil spring, in both types dublet, the better time have been achieved by shooting with heavy munitions. It appears that the lightest "kick" harder the shooter (although at the measurements of said factorial force at the IPSC lightest they will have smaller force, that is to say theoretically will also be worse).
5. We can realise, that with the application of system the dublet with lighter munitions, are faster, than with the heavier munitions, with the conventional spring and with the magnetic - mechanic system as well.

The first remark, after using the "Magnetic - mechanic system of recoil reduction of gun" is, that the work of mechanisms is not disturbed - something, that at first was not by no means sure, on the contrary, we expected some problems in the gun's operation. That kind of mechanisms often causes various problems. In the case in question we have shot some hundreds shots and did not come up any problem, no jam. In addition our subjective impressions in the subject of tested system interface.

First of all is perceptible the difference between the force of conventional recoil spring and the force of mechanism with combination of springs and magnet, from the moment of arming. For the arming of gun with the tested system installed, it should be used much more strength than usually.

Upon firing, the gun that is equipped with the system behaves completely differently than the gun without it. The recoil and the "kick" are gentler, like it is softer. Simply, the pistol "kicks" less in both kinds of munitions.

Does it worth to be equipped with this system? We believe that each one firstly should tested it by himself and then to make a decision. We inform the interested, that the Constructor and inventor of mechanism is the Greek company DPM Systems Technologies, which can be found in the Internet, in the address www.dpmsystems.com and www.glockuser.com, which manufactures also these systems for some other of the most popular pistols, however without magnetic support. The price of the whole system for the pistol Glock, purchased directly from the Constructor, costs 99 Euros.

We thank Company HEGE for the concession of the chronoscope for the tests that were conducted by the Authors.

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