Load Development Method

Load Development Method

01/27/2005

The objective of my load development method is to determine the mixture of components and the specifications of their assembly in order to produce a round that will perform at sub-moa levels out to 1000 yards. This immediately turns into an optimization problem. My sense is one will almost always be faced with compromising one characteristic of a load in order to achieve an acceptable performance level in another facet of the load. For example, I think a typical compromise would be the need to give up some on the ability of a load to group well at 100 yards, in order to produce a velocity that will keep the projectile supersonic at 1000 yards.

My method is as follows;

Step 1. Determine the spread of charges I wish to test and work loads over that spread in 0.3 gr increments. The determination of the charges to start with can be made several ways. Currently I use Quick Load and the Optimum Barrel Time Method

to determine a starting point. See the link for details. Then I use a modified version of Dan Green's Optimum Charge Weight Process at the range.

Step 2. I fire these loads through my chorongraph at targets setup at 200 yards. Each target is aligned in the same horizontal plane. I measure to the nearest 0.1 inch each group size, then I locate each groups' center point and measure the vertical distance between the centers' of each adjacent group. See the picture below. The vertical distance between the group on target C1 and the target on B5 is 3/8".

Step 3. Then I lay the data out in tabular form to determine the two fastest loads with the tightest groups and the smallest vertical measurement, i.e. the least vertical dispersion. Note, in the table the Vert. Disp. measurement is the distance between the group's center (POI) and the center of the target (POA).

200 yd Data

Step 4. Take the two loads determined in step #3 and work-up loads in 0.2 gr. increments and repeat the above process to determine the final load. This final load should be the fastest and tightest shooting load that has the most resistance to fluctuations in powder charge and/or environmental conditions. I do this while at the range using my portable bench setup shown below. From this point I can enter

into the fine tuning phase of the load development process and try different primers and then bullet seating depths.

After I have the load developed that I think I want to go into production with I take a target out to 300 yards and try shooting there for groups. The final test is a F-class shoot where I get to test out to 1k yds.