Sergiy Kravchenko (december 2007)
This article not has been published in magazine "International Freediving and Spearfishing News" . www.diving-action.com
The shooting accuracy table of various spear guns.
The initial purpose of article was definition of the shooting accuracy of various spear guns. Having received results of shooting, for enough big of a spear gun arsenal, I have added in the table a number of a spear gun characteristics and have received in a result … my reasonings about influence of design features of a spear gun to the shooting accuracy.
The shooting accuracy is expressed by the rectangular area, that contain all holes in a target, and the sides of rectangular pass through the centers of lateral holes and lines were carried out in parallel and perpendicularly to horizon. The first figure shows height of the rectangular, the second - width of it. The sizes - in centimeters. From everyone gun it has been carried out on 5 shots on a shooting distance of 2 meters (Table 1). From three most powerful guns it has been carried out on 5 shots on a shooting distance of 4 meters (Table 2). For me it was very interesting to find out shooting accuracy of guns with a forward binding of a spear and on this, it has been carried out also on 5 shots from such guns on a shooting distance of 2 meters (Table 3).
Certainly, having made a lot of shots, we would receive more exact results, but the most important result of these researches is that we have the numerical characteristic of the shooting accuracy of a gun under natural conditions of the underwater hunting. Now we can compare various guns and to choose this gun on concrete parameter of the shooting accuracy.
The shooting distance was equaled to distance from a spear tip up to a target and there were two or four meters. The target represented a square sheet of dense rubber in width 50х50 cm and thickness about 7 centimeters. For fixing holes from shooting, to a target fastened 50х50 cm a sheet with a contrast point in the center. On this point of arrows made an aiming at shooting on a target.
Thus we made measurements of a speargun loading effort.
In article is not given the information about the location of the target centre within the rectangular area found for each gun, as it would be interesting only to corrective action of the aim adaptation of the gun.
The tests was done in a swimming pool. Shooting was made publicly, same underwater hunter, in conditions completely identical. Shooting was made without the machine tool. Underwater hunter stood at the bottom, having omitted a head under water, and aimed through a gun receiver to a target, that having reduced up to a minimum an aiming error. All spears have been supplied unary a tip.
The guns for tests were from owners which now actively and a long time are engaged in spear fishing in the Dnepr river and similar fresh-water area of Ukraine. I have taken advantage of a case to compare these capacities of a gun. And about a miracle, appeared, that all have unanimously chosen guns capacity about 50 joules. I so have understood, that the overwhelming part of underwater hunters very much confidently feels itself with such weapon, and safely get involved in fight with any trophy fish. In this plan, certainly, the spring RPO-1 gun with the 8 joules – it is modestly, but the veteran should be we respect …
The spring RPO-1 speargun.
The arsenal of spearguns.
So, we shall not distract from the main thing … though the main thing is hunting, and concept of hunting at everyone the … so we it about what?.. About, has recollected - shooting accuracy!!!
Table 1
The speargun |
PVR 500, pneumovacuum |
Zelinka 370, pneumatic |
RPS-3, hydropneumatic |
EF 500х10, hydropneumatic |
Arbalet Imersion 600 |
OMER Tempest 500, pneumatic |
Zelinka 450, pneumatic |
Aquatech 500x9-B, hydropneumatic |
Zelinka 645, pneumatic |
Grip handle position |
rear handle |
middle handle |
rear handle |
rear handle |
rear handle |
rear handle |
middle handle |
middle handle |
middle handle |
Loading effort of speargun, kgf |
25,5 |
20 |
24 |
78 |
30 |
30 |
13,7 |
40 |
13,4 |
Working course of spear, cm |
37 |
30 |
40 |
50 |
29 |
38 |
41 |
50 |
52 |
Diameter of spear, mm |
7 |
7 |
9 |
8 |
6,5 |
8 |
7 |
8 |
8 |
Weight of spear, kg |
0,18 |
0,11 |
0,29 |
0,26 |
0,26 |
0,23 |
0,16 |
0,23 |
0,30 |
Speed of spear, m/s |
27,5 |
28,4 |
18,7 |
40,6 |
19,4 |
23,4 |
24,2 |
30,8 |
18,7 |
Energy of spear, J |
67 |
43 |
50 |
206 |
48 |
62 |
46 |
107 |
51 |
Time of working course of spear, s |
0,022 |
0,017 |
0,035 |
0,020 |
0,025 |
0,027 |
0,028 |
0,027 |
0,046 |
Accuracy of shooting, cm |
h < w 5,0х8,9 |
h < w 5,3х7,2 |
h > w 6,1х3,5 |
h > w 6,5х5,6 |
h > w 7,5х5,8 |
h < w 8,1х9,4 |
h < w 10,6х13,2 |
h > w 12,8х8,2 |
h > w 13,1х3,5 |
Distance of shooting, m |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
Binding of spear |
Rear |
Rear |
Rear |
Rear |
Rear |
Rear |
Rear |
Rear |
Rear |
Analyzing forms of the rectangles containing all holes in a target, we shall notice, that height of the rectangle greater than its width “h > w” (Table 1). It is naturally and it is the recoil effect of the gun, that causing the muzzle to lift with the shot. It is not naturally, where height of the rectangle less than its width “h < w”. I can explain it only absence of aim adaptations on these guns. An error of an aiming of these guns is more in a horizontal plane, than in vertical. Confirming this version is the RPS-3 gun with the high-grade aim adaptation, where an error of an aiming is identical in a vertical and horizontal plane. The RPS-3 gun has very good result on accuracy in a horizontal plane and the height of a rectangle exceeds its width “h > w”.
The hydropneumatic RPS-3 speargun.
The OMER Tempest 500 gun has good aim adaptations, but nevertheless height of the rectangle less than its width “h < w”. I would explain it that the gun has high pressure of compressed air for the greater capacity of a gun. The gun therefore has hard descent of a trigger hook and it has affected the shooting accuracy.
The pneumatic OMER Tempest 500 speargun.
Certainly it is my assumptions, but soft descent of a trigger hook and good aim adaptations of a gun is a pledge of best the shooting accuracy.
The pneumovacuum PVR 600 speargun.
Family of pneumatic spearguns of a Zelinsky system.
The hydropneumatic Aquatech 500x9-B speargun.
The Zelinka 800 and Aquatech 750x9-B guns have no aim adaptations, but due to the big length of a gun have approximately identical error of an aiming in a vertical and horizontal plane. These guns have height of a rectangle more than its width “h > w” (Table 2).
Table 2
The speargun |
EF 500х10, hydropneumatic |
Zelinka 800, pneumatic |
Aquatech 750х9-B, hydropneumatic |
Grip handle position |
rear handle |
rear handle |
mid-handle |
Loading effort of speargun, kgf |
78 |
20 |
26 |
Working course of spear, cm |
50 |
73 |
75 |
Diameter of spear, mm |
8 |
7 |
8 |
Weight of spear, kg |
0,26 |
0,24 |
0,35 |
Speed of spear, m/s |
40,6 |
31,5 |
26,2 |
Energy of spear, J |
206 |
115 |
118 |
Time of working course of spear, s |
0,020 |
0,038 |
0.047 |
Accuracy of shooting, cm |
h > w 12,9х11,1 |
h > w 13,8х7,1 |
h > w 16,5х14,7 |
Distance of shooting, m |
4 |
4 |
4 |
Binding of spear |
Rear |
Rear |
Rear |
The hydropneumatic Aquatech 750x9-B speargun.
The pneumatic Zelinka 800 speargun.
One more conclusion is interesting - if the recoil effect of the gun leads to the greater disorder of hits on a vertical then it is more favourable to hold the pistol grip handle of a gun in parallel a fish spine and the probability of hits will in a fish more.
Comparing influence of an disposition of the pistol grip handle on a gun, we see, that the guns with mid-handle have considerably smaller the shooting accuracy than the guns with rear handle.
But the Zelinka 370 gun with mid-handle obviously "spoils" a picture … The Zelinka 370 gun have small weight of a spear and have big speed of a spear. I had the idea to calculation the time of a working course of a spear for all the guns. Results of these calculations are the « Time of working course of spear, s. » table. We have the obvious tendency – if less the time of a working course of a spear, then more the shooting accuracy. Due to small time of a working course of a spear the Zelinka 370 gun with mid-handle has great the shooting accuracy among other guns with rear handle. Analyzing the shooting on 4 meters distance, we notice harder the tendency is than less the time of a working course of a spear, then more the shooting accuracy.
The pneumatic Zelinka 370 speargun.
Here, I would draw a unequivocal conclusion, that for increase of the shooting accuracy of a spear gun it is necessary to reduce weight of a spear and (or) to reduce a working course of a spear, that is, to lower the time of a working course of a spear.
Comparing the shooting accuracy depending on power of a gun, we see, that the increase the power of a gun does not almost influence shooting accuracy of a gun. For me it was unexpectedness. I thought, that more powerful gun has bigger the recoil effect of the gun and consequently has the greater causing the muzzle to lift with the shot. The EF 500х10 gun has 206 Joules energy, it is in almost four times more than guns with a working course of a spear up to 50 centimeters and in almost two times more than guns with a working course of a spear up to 75 centimeters. In result the EF 500х10 gun has the best shooting accuracy among a gun with a working course of a spear up to 75 centimeters and has the good shooting accuracy among a gun with a working course of a spear up to 50 centimeters.
The hydropneumatic EF 500x10 speargun with rear handle.
From all tested of guns, I distinguish the rubber 600 gun as about legends of shooting accuracy of rubber guns … more precisely was legends. In practice we see, that rubber guns, at least, private the soldiers rubber guns with which at us hunting, especial accuracy do not differ. But here it is possible to make one conclusion, that accuracy about 8,0 centimeters on a 2 meters distance of shooting is quite comprehensible to overwhelming number of underwater hunters.
Arbalet Imersion 600.
From the received results I so have estimated shooting accuracy of a spear gun on a 2 meters distance of shooting:
- Excellent - up to 3,5 centimeters;
- Very good - up to 5,0 centimeters;
- Good - up to 8,0 centimeters;
- Satisfactory - up to 13,0 centimeters.
Table 3 The speargun RPS-3, hydropneumatic Spring 600 speargun RPB-1, pneumatic Grip handle position rear handle middle handle middle handle Loading effort of speargun, kgf 24 20,7 19 Working course of spear, cm 40 16,5 43 Diameter of spear, mm 9 8 8 Weight of spear, kg 0,29 0,24 0,25 Speed of spear, m/s 18,7 8,5 18,4 Energy of spear, J 50 8 41 Time of working course of spear, s 0,035 0,032 0,039 Accuracy of shooting, cm h > w 24,0х23,2 h > w 28,2х25,0 h > w 31,8х24,3 Distance of shooting, m 2 2 2 Binding of spear Forward Forward Forward
We see, that the guns with the forward binding of spear has significant deterioration of shooting accuracy (Table 3). The RPS-3 gun at a forward binding of spear has shooting accuracy 24,0х23,2 cm. That is in almost four times worse , than at a rear binding of spear (shooting accuracy 6,1х3,5 cm). The RPB-1 gun has almost identical horizontal accuracy of shooting in comparison with the RPS-3 gun with the rear handle, but as the RPB-1 gun has the middle handle, that therefore the vertical accuracy of shooting has worsened almost on 8 cm still.
Above it is the rear binding of spear. Below it is the forward binding of spear.
The pneumatic RPB-1 speargun.
Recollecting the underwater hunting with the RPB-1 gun and having now the objective data on shooting accuracy of this gun, I can not take in sense, how I could then in general to hit a fish??? Probably, only due to the trident!!!
Having characteristics of accuracy of shooting various the guns, we can compare them with areas of defeats of various fishes. The brain or spine, in which will instantly paralyse a fish, have the smallest area of defeat and demand very exact shooting of a gun. Fleshy sites of a fish body have bigger area of defeat and consequently requirements to accuracy of a gun can be reduced. Use of tridents for a spear raises probability to hit a fish. Unfortunately, there are no some more other ways to compensate lack of accuracy of a gun. Though the "genuine" underwater hunters always have a chance to casual hit of a fish.
In conclusion of article, I would like to wish you successes in your hobby for spear fishing and to not overlook to compare the sizes of a fish with shooting accuracy of a spear gun.
Vitaly Babichev - the creator of pneumatic spearguns Zelinka 370 and Zelinka 800.
Edward Fantaev - the creator of a hydropneumatic EF 500x10 speargun.
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