Frans Dreyer , Manager Senwes Grain Brokerage is the author of this column . |
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It is , however , important for the reloader to ensure that all components meet the required specifications and manufacturers ' recommendations for the specific calibre for which the load will be developed .
Following the above , the minimum load for the selected bullet and type of gunpowder as recommended by the powder manufacturer , will be the point of departure . Load one bullet with the minimum load and thereafter one bullet in increments of 0.2gr or 0.3gr . As a rule 0.2gr increments are recommended for calibres smaller than 6mm and 0.3gr for calibres larger than 6mm . However , you may find the right answers much faster by using 0.2gr increments . Suppose the recommended minimum load is 40gr , then the successive loads will be 40.2gr , 40.4gr , 40.6gr etcetera , until the maximum recommended load is achieved .
Each of these rounds will be shot at 300 m by aiming at the same marker on the target every time . Should the magnification of your telescope not necessarily be suitable to shoot at 300 m , 200 m would also be acceptable . The reason for the 300 m is mainly to distinguish better between the vertical distribution of the rounds on the target . It is therefore important to carefully mark every round on the target .
The challenge of walking 300 m to the target to mark the shot every time has also been overcome in a number of innovative ways . Some shoot-
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ers make use of a video camera which records the process and which allows the shooter to indicate the shots at his leisure by watching the video . Others mark the bullets by colouring them , using different coloured permanent markers . Each bullet hole can be identified by linking the colour to the load concerned . However , it remains important not to rush the process and to allow the gun barrel to cool down between shots .
The objective of this exercise is to evaluate the vertical distribution of the shots and to identify the areas where shots bundle or where the vertical distribution is small . The theory is then that three or four loads of the shots in the bundle should be selected , whereafter five rounds of each chosen load is loaded . These loaded rounds are then shot over 300m , after which the best load can be identified , based on the smallest group . Three shots as a group test can be regarded as sufficient but a human error or the influence of environmental factors may results in uncertainty about “ that one ” shot . It is therefore better to use at least 4 shots to make sure of a group .
As far as load development is concerned , it is also important to minimise the vertical distribution of shots of the same load as far as possible . The shots must , as far as possible , be on the same hori-
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zontal line on the target but the horizontal distribution should also not be too wide should environmental conditions such as wind , mirage and light not have had a significant impact . This process can be explained meaningfully by making use of the following example .
LADDER EXAMPLE While searching for an alternative hunting load for my . 308 , I tried the product of a local bullet manufacturer . I like using Sonchem S335 gunpowder and the bullet weight is 165gr . Should this have been the first time that I used 165gr bullets in my rifle , I would have started at the closest bullet weight recommended by the gunpowder manufacturer ( 168gr ) and I would have started at a load of 37.4gr and worked up to 41.5gr in 0,3gr increments . However , it has become clear to me over time that the best load for my rifle is between 40gr and 41,6gr for 165gr bullets . I decided to explain this specific example since fewer shots were fired , but more than one potential sweet spot materialised visually . Under normal circumstances it remains of the utmost importance to start shooting at the minimum load and to gradually work up to the maximum load . Look out for any signs of pressure and do not fire a higher load should any signs of pressure be experienced .
The ladder was shot at 200m and every shot was aimed at the orange circle in Figure 1 . The vertical distribution indicates that shots 1 , 2 and 3 form a
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