Originally Posted by
bronko22000
So I think what you're looking for in this test, the way you did it, is to look for groups which had the smallest spread in velocity within that group and a pair of groups that exhibited the smallest difference in velocity?
Sorry for picking your brain. But this is very interesting and I'm sure a lot of other members are checking it out too. In all my years of reloading I was content with my method of load development. Its just been in the past month or so that I've been doing a ton of research on different techniques. What I was doing in the past was good for 100-200 yards because that's all I ever shot. Now that I want to get into long range shooting my method, to put it mildly, 'sucked"! Some rifles I got lucky with, others, not so lucky.
I have done the Newberry OCW test, and the Audette Ladder test, extensively in the past. The last two years, I've almost exclusively used the Satterlee Velocity method. I shoot at that "OCW style" target, just to give me an idea of how the groups are looking - really just to tell if I need to clean my rifle or not.
So... What SHOULD be done for an OCW test:
Line up horizontally as many target/POA's as you have incremental loads, planted at 300yrds. Shoot round robin, 1 round at each target. When finished with 3-5 rounds through each string, mark the center of each group. Then the method starts - you observe the shape of the "wave" between the centers of each group. You want to pick a load from a "flat spot" in the wave. The idea - the flat spots represent a node, meaning the slight variabilities inherent to your loading process and components won't result in as much vertical dispersion at range. Slight variability in neck tension, bullet weight, case volume, charge weights, etc... It all gets muted by falling within the node. Alternatively, loading at a wavy part of the wave would mean your load is vulnerable to increased vertical dispersion due to any of these variabilities.
Alternatively, I have been using the Satterlee method the last two years for my competition rifle, which has served me very well for long range, precision rifle competition.
For the satterlee method, you don't even need a target, just a chronograph. Shoot your incremental loads, plot the velocity curve, look for flat spots, and load in the node. The logic is a little simplistic - it effectively assumes a rifle will shoot small, simply by choosing a good bullet and putting it at the appropriate jump, so velocity consistency is the important output variable.
Since any shooting should be done at a target, I hang up a target and shoot my Satterlee method on it. Since each load is independent, I shoot independent POA's, which gives me an idea how well my rifle is grouping at that point in time (barrel life, throat erosion, copper & powder fouling). I don't put too much stock into the group sizes or shapes, but focus on the velocity curve.
Both methods work, but I can complete the Satterlee method at 100yrds effectively and efficiently, and have little dependence upon shooter influence. And do it with less rounds than an OCW or ladder.