Hi Kyle,
I absolutely agree with the Ladder Test process, in windy conditions it can make it challenging to interpret the information that you get out of it, but it tends to work well. Sometimes when the bullet "climbs" the wind it can make it a little harder but there are times when you just have to work with what you have available to you.
I am lucky here in Canberra, Australia in that I have access to two ranges, both ostensibly open 24/7, so I can look at predictions for wind in the next couple of days and plan my testing around when there will be reasonable conditions as much as possible, we have a good group of shooters that work together for things like this, so will set up the range very early on a Saturday morning to do load testing together.
I did the ladder test process earlier this year for my 6mmBR early one morning on Kongsberg electronic targets at 300m, I set up a friends LabRadar next to the firing point and video'd the process of the ladder tests with my iphone, the video captured the monitor of the Kongsberg system as well as the LabRadar output screen, so I could capture the shot placement in x/y co-ordinates on the E-Target monitor as well as the velocity for each shot. This is an awesome use of the technology, and it allows you to go away and interpret the data at a later time.
Before the ladder test I did the Berger jump test, testing 10, 50, 90 and 130thou jump, then did the ladder test with 10 loads between 29.4 and 31.2gns of AR2208 (Varget) using the best jump from the jump test.
I have plotted the results into Excel, you will see in the attached image that the bottom of the graph shows the powder load, the other axis of the graph is the elevation in millimeters (sorry, I'm a metric child)
You will note that I have circled the two loads that I thought showed promise, both were consistent in the separate strings (the middle of three shots that didn't vary wildly in elevation) AND consistent between the two separate ladder tests.
I urge you to now go and test Jump again, I thought I had settled on a load - 29.8gns Varget and 90 thou jump with a 105 Berger VLD, but at 500m I would get 4 shots into around 25 - 30mm and one shot out to blow that 5 shot group to 60 or 70mm (just over an inch to around 3") and both 29.8 gns and 30.4 were doing the same thing to me.
I called my gunsmith (and good friend), Russell LeMaitre as I was perplexed. His advice was to try jamming the projectiles, this is something I have always avoided as I have had good success getting the Berger VLD's to shoot without jamming into the lands. I was desperate, it was two weeks before the Fly Nationals here in Aus, and I was travelling (flying thankfully) 3700km (2300 miles) to Perth on the opposite side of the country with a rifle that wouldn't shoot acceptable groups. It just wasn't a winning combination. I listened to Russ and went ahead, trying 20 and 40thou jam. I am very pleased I did, 20 thou jump gave me a couple of 3 shot 8mm groups at 200m as opposed to over 25mm (1") for the 90thou jump load (I had to try this at shorter distance because the conditions were pretty rough and I was just out of time)
The rifle performed well enough for me to take out the win for Light Gun at the Nationals, so it was time well spent, and the ladder test was fundamental to me finding the load initially.
Cheers.
Dave Groves.
Canberra