Working Up a Load

Every weapon shoots a little differently, and, of course, every different bullet and/or powder load will affect accuracy as well. If a shooter only wants to shoot the typical government load for his weapon in an effort to recreate its operation as authentically as possible then working up a load is not necessary and he can simply work on improving his accuracy with that load, but if he wants to find the most precise load for his specific piece then this procedure will help determine what works best.

Working up a load refers to the process of testing various combinations of loads until one is found that reliably produces the best Figure of Merit (to learn about the FoM and how to calculate it see historicalshooting.blogspot.com/2021/01/calculating-figure-of-merit.html). Many shooters only consider group size, but as the essay linked above will show, the FoM is much more useful for this.  Once that is determined the shooter can work on adjusting his sights and/or aiming off in order to bring his Mean Point of Impact to the Intended Mean Point of Impact.

Sample chart.

To work up a load, prepare several batches of ammunition. The powder used (Swiss, Schuetzen, Goex, Pyrodex, etc.), the granulation of the powder (1F, 2F, 3F, etc.), any filler used to fill the case (wool, corn meal, etc.), whether grease cookies ae used or not, and the bullet type can all be varied, but only change one thing in every batch. Each batch should have at least five rounds in it; the commonly seen three-round batches are statistically insufficient, and ten rounds would be even more precise (see youtu.be/Ahp_bw5ZGjk).

Make a chart listing each load, as shown above. In this example, we consider two kinds of bullets (ring-tailed and Richmond Labs) with two different kinds of powder (Swiss and Schuetzen) and three different powder loads (55, 60, or 65 grains of each brand) for the 1859 Sharps Infantry Rifle.  Of course, this can be expanded with many different loads, but that will require a lot more test batches of at least five rounds each—this chart should only be seen as an example. Then, too, the test can be conducted at different ranges since a load that shoots well at 100 yards may not do so at 500 yards, so a completely different chart would have to be prepared. As this makes plain, the working-up process can be extremely involved and require a lot of ammunition; note that just working through the chart shown will require 60 rounds.

Next, take the chart and the ammunition (clearly marked) to the range. Since this is a test of precision rather than of accuracy (i.e., how the ammunition shoots from a given piece rather than how well the shooter shoots), all firing should be done using a rest to take the human factor out of the equation as much as possible. Make certain to use exactly the same Point of Aim and Sight Picture for each shot.  Calculate the Figure of Merit (see the link above) for each table of fire (in other words, each five-round test batch) and it will be obvious which load works best for that firearm at that range. Once the optimum load has been determined the sights can be adjusted and/or the principles of aiming off can be used in order to bring the Mean Point of Impact as close as possible to the Intended Mean Point of Impact with every round. After that, it’s a simple question of frequent, consistent practice to improve the results.