TENRINGS

Bench testing a Steyr LP1 air pistol

For some considerable time, many of our club air pistol shooters have often wondered how much positional deviation is caused to the pellet by variations in muzzle velocity.

There have been several efforts made at checking the muzzle velocity with a chronoscope to try to determine the most consistent brand, size and weight of pellet under the prevailing ambient conditions at the time of the test. All of these tests have been carried out with the pistol held in the hand, as that was the easiest way for these simple tests to be executed.

The subject of bench testing had often been discussed, but had never been actioned, due to lack of time and range space.

It was decided to persue these ideas further. A substantial pistol clamping bench was created and situated 10 metres from the target in the hope that some realistic information could be learnt from the exercise.

As the previously mentioned batch selecting tests had been carried out, it was decided to use Air Arms 4.49mm diameter 0.475grams pellets as these had shown to be the most consistent muzzle velocity when used with the Steyr Sportwaffen LP1.

The following shot patterns were obtained with a pre-charged Steyr LP1 air pistol clamped in the bench test. The testing was carried out to try to establish the correlation between the muzzle velocity and the resultant group size and relative position on the target.

Adjustments were made to the air pressure regulator after each 5 shots, a stabilisation shot was fired after each adjustment and before the next series of readings were taken.

All readings were taken using a Combro CB625 chronoscope. The air cylinder for the pistol was pre-charged to 200 bar before the first tests were carried out. As only a total of approximately 80 shots were fired, there is no reason to doubt the consistency of the air supply to the pistol.

The ambient temperature was 10deg c and the relative humidity was 55%. It is not expected that there would be any significant variations to the results with changes in the ambient temperature conditions, however changes in relative humidity and subsequent density of the air may change the relative position of the shot on the target, but should not affect the group size.

The first tests were taken with the air pressure/muzzle velocity set as had been last used for normal shooting. Subsequently the muzzle velocity was gradually reduced to a point where the performance might be expected to fall off.

The final tests, were the results obtained by resetting the air pressure to maintain a muzzle velocity of approximately 525 feet per second, as the tests appeared to indicate that the best groups were obtained at this muzzle velocity. All figures in the tables are in feet per second for convenience. These could be converted to metres per second if required.

To convert muzzle velocity into muzzle energy use the information in the following link: Muzzle energy

510FPS

515FPS

520FPS

522FPS

528FPS

530FPS

532FPS

535FPS

525FPS

This may sound somewhat grandiose and mysterious and dependant on your outlook, it may well remain so.

At any given point in a timeframe i.e. whilst shooting either in training on in a match, the actual score of the single shot or string will be the direct result of your mental approach, preparation and attitude at the time of shooting, combined with your highly skilled and pre-trained ability to release the shot to the best of your capability.

Once the shot has been released and has cleared the barrel, there is nothing else that you can do to influence the final outcome and position on the target, i.e. ‘what will be, will be’.

Is there something that can be learned from the outcome? Short term: The score, the position of the shot, feeling of a degree of achievement and/or others.

However, in the long term analysis, this is where we can utilise our “Esoteric Potential”. This is possibly best described as the means of calculating your achievement in relation to a few established and known factors. This provides a means to quantify and hopefully improve your scores. By improving your “Esoteric Potential” your overall scores and achievements will also improve.

How to calculate your “Esoteric Potential”.

You need to determine a base score, this needs to be your lowest acceptable individual shot score, for example “9”. If you manage to shoot 10 consecutive “10’s”, you will have a gun score of 100, that’s the easy bit. Your maximum potential score can only be 100 and your string average is 100. That's pretty boring and not difficult to calculate.

If you are fortunate enough to be able to shoot on "electronic targets", you will be able to use the decimal points to create a tighter challenge, ie 9.3 or 9.7 as your minimum acceptable score. As always, make the goal an achieveable one.

If you have a gun score of 95 with five “10’s” and five “9’s”, your maximum potential score is 95 and you will have an “Achieved Potential” of 100% on this particular string. If however, you achieved this 95 gun score with six “10’s” three “9’s” and one “8”, your maximum potential score is 96, which has an “Achieved Potential” is 98.96%. A further example, you score 98 with nine “10’s” and one “8”, your potential score is 99 and you have an “Achieved Potential” of 98.99. Conversely, if you have a gun score of 93 with five “10’s”, three “9’s” and two “8’s”, your potential score is 95 and you have an “Achieved Potential” of 97.89.

Once you have fired a few strings, it is then possible to calculate your average potential score and average achieved potential. The object of the exercise is to use the analysed data as a means of feed back to quantify your improvements.

You have now created your “Esoteric Potential”. The object of the exercise is to improve your overall gun score, whilst trying to obtain an “EP” of 100% by reducing your group size.

Score improvements will only be achieved by interpreting the results and then systematically eliminating some of your errors and continuing to practice your complete release technique.

Do not attempt to carry out the analysis whilst trying to concentrate on your shooting; you could end up trying to out think your self with the innevitable adverse result.