Gurus Grumbles
"Maths" for sight alterations - Part 2.
Do the Maths for sight alterations - Part 2.. In afterthought from the previous grumblings. One of the things that can help the mathematics of reaching the vee bull from where ever the shot fall happens to be is a good set of plot sheets. Our intrepid web admin has probably the best I have seen for full bore. His are range specific, and mapped out in minutes of angle, together with some accurate information on wind values in terms of wind speed and direction. They also have space for notes set aside as well. Just using these plot sheets is a huge learning experience, (including those that shun them, myself included) as the information concerned relative to measurements of shot fall is far easier to work out rather than trusting the memory. There is a method for using the plot sheets, and it does become part of the shot ritual after training with them for a while. The method is simple and with the plot sheet fixed with a dog clip along side of your position as you fire the stage of shots, it goes like this. The first sighter is fired after the preliminary details are noted (EG. Wind arm points on the sight, elevations, sighting variables such as filters etc). The decision is made to alter the sight if necessary, and the second sighter fired also. Once the second shot is down range, and the mirage/flag observations made, the position of the first sighter shot is entered on the plot sheet in the time when the target is lowered and marked in the butts. The target reappears, the second sighter is observed, the movements on the sights made (if any) and the decision made to keep, or cut, your sighter shots. The next shot is fired, and the details of the second sighter is recorded, once more while the target is being marked in the butts, and so the ritual continues until the stage of shots is completed. This method does not waste time, and provides a very good ?heads up? of relative information to help manage the progress of the shoot. The plot sheets can also help if there is any dispute concerning the number of shots fired due to inattentive scorers (which sometimes happens.) But, in terms of the mathematics which is the theme of this grumblings, it is very easy to reach a decision about the mathematics concerned with centering the group, or reaching the Vee bull in case a shot is well away. Colin?s plot sheets are set out accurately in minutes of angle so you can work out exactly how far the shot hole has landed relative to the scriber hole of the target. Then it is a simple matter to read the sight alteration much more accurately than with an educated guess, and make the correct adjustment. Good plot sheets are mandatory for a wind coach to use in a coached Teams Match. It is far easier if they have the plot sheets available that are both accurately divided into minutes of angle, and have wind and weather information available to see at a glance. You can also watch the group form, and make the adjustments to make sure the stage of shots take advantage of any irregularities in wind judgement, or centre the group very accurately to take the best options that develop. You can also trace a lot of information concerning rifle and ammunition performance, as well as your own personal performance. Any sort of information is valuable, and can often come from the analysis of your plot sheets. In my opinion there are very few comprehensive diaries kept by full bore shooters.This is costing progress, believe me, and the plot sheets are a start, if only to get a much better idea of the mathematics involved in decision making to centre the group. Guru