I'm not only a photographer, I'm an analyst by profession. I gravitate to hard core analysis when I shoot, even keeping a log of every shot and where it went. Anal is the prefix to analyst so sue me! After reading a a very recent and pretty comprehensive article over at PRB on statistical analysis as it concerns rifle shooting I downloaded the free trial for the OnTarget TDS software today. I really recommend this PRB 3 part series. It is chock full of good information. I also recommend that if you're going to read more than one of the three parts nonstop to get a pot of coffee going! There are a lot of quotes included in there from some of the foremost experts on this subject, including Brian Litz, and so I highly recommend the series.
Putting the PRB three part articles and the OnTarget software together was an eye opener. Luckily, I had saved some of my targets from previous shoots so that I was able to use them for testing and analysis. Having saved some of the targets I've shot with my .22 Magnum trainer I was able to put together a picture that matches the articles to a tee. Makes me a believer, at least until I get additional data but that's not likely to contradict the results.
Here are the link to the first PRB article post. You can find the rest on the follow up links:
https://precisionrifleblog.com/2020/11/29/statistics-for-shooters/
Downloaded the software and got to work. I did not cherry pick my groups. Actually, the opposite is true. I can show you some .4 MOA 5 shot groups at 100 yards but I purposely picked the average/worse groups, so I could see what patterns emerged. The software allows you to superimpose multiple groups which is superb. The end result is that you can shoot different groups any way you want, in my case, 2, 3 shot groups per target and aggregate them over a number of targets into one virtual target. Just happens that this is exactly what I had done. I shot 3 shot groups, reloading in between, 2 groups per target. Most of the time......
All shots were made at 100 yards and aimed at 1.5 MOA targets, with a 1/2 MOA center circle and a 1/4 MOA diamond inside of that. Here is what the target looks like (I print my own):
OnTarget has a "virtual" target display that does not include the actual target image. Once the software figures out (with your input) where everything is it generates a virtual target/impacts along with a TON of very meaningful data, including mean radius and CEP (Circular Error Probable) numbers. The US Army uses mean radius exclusively in their evaluation of all weapons. We all use extreme spread, which is good, but not really so much for statistical probability of where your next shot will land. This is because extreme spread weighs outliers in the groups much heavier than the rest of the shots. The original is always available if you need to look at it, but for analysis it becomes superfluous This virtual mode is the mode I used for analysis.
So on to the targets. The targets were made shooting 2 - 3-shot groups into 5 separate targets. The number of shots varied and I actually lost a shot somewhere because the numbers of shots do not match multiples of three by two shots.
This is the first virtual target - 2, 3 shot groups with a LOT of important numbers, including mean radius, SD, and CEP. I wont get into that, you'll have to read the articles
!
But look at what happens when I added 4 more 3 shot groups (losing one shot somewhere) for 17 shots:
At this point it looked like I had some fliers. Fliers are what most people don't count. In this image it looks like there at 2 fliers (bottom center left). So do I take them out? Look at what happens when I overlay more groups:
Now I'm up to 11-3 shot groups. Lost another shot somewhere (again) so it becomes a 31 shot group. The important point here is that the shots that looked like fliers are not anymore. They are grouped so -- no flyers. By the way the light purple circle is not an MOA or inch measurement, it is SD and CEP related. CEP (Circular Error Probable) is an excellent measure of accuracy and precision. I want more!
All the best,
JAS
Putting the PRB three part articles and the OnTarget software together was an eye opener. Luckily, I had saved some of my targets from previous shoots so that I was able to use them for testing and analysis. Having saved some of the targets I've shot with my .22 Magnum trainer I was able to put together a picture that matches the articles to a tee. Makes me a believer, at least until I get additional data but that's not likely to contradict the results.
Here are the link to the first PRB article post. You can find the rest on the follow up links:
https://precisionrifleblog.com/2020/11/29/statistics-for-shooters/
Downloaded the software and got to work. I did not cherry pick my groups. Actually, the opposite is true. I can show you some .4 MOA 5 shot groups at 100 yards but I purposely picked the average/worse groups, so I could see what patterns emerged. The software allows you to superimpose multiple groups which is superb. The end result is that you can shoot different groups any way you want, in my case, 2, 3 shot groups per target and aggregate them over a number of targets into one virtual target. Just happens that this is exactly what I had done. I shot 3 shot groups, reloading in between, 2 groups per target. Most of the time......
All shots were made at 100 yards and aimed at 1.5 MOA targets, with a 1/2 MOA center circle and a 1/4 MOA diamond inside of that. Here is what the target looks like (I print my own):
OnTarget has a "virtual" target display that does not include the actual target image. Once the software figures out (with your input) where everything is it generates a virtual target/impacts along with a TON of very meaningful data, including mean radius and CEP (Circular Error Probable) numbers. The US Army uses mean radius exclusively in their evaluation of all weapons. We all use extreme spread, which is good, but not really so much for statistical probability of where your next shot will land. This is because extreme spread weighs outliers in the groups much heavier than the rest of the shots. The original is always available if you need to look at it, but for analysis it becomes superfluous This virtual mode is the mode I used for analysis.
So on to the targets. The targets were made shooting 2 - 3-shot groups into 5 separate targets. The number of shots varied and I actually lost a shot somewhere because the numbers of shots do not match multiples of three by two shots.
This is the first virtual target - 2, 3 shot groups with a LOT of important numbers, including mean radius, SD, and CEP. I wont get into that, you'll have to read the articles
!
But look at what happens when I added 4 more 3 shot groups (losing one shot somewhere) for 17 shots:
At this point it looked like I had some fliers. Fliers are what most people don't count. In this image it looks like there at 2 fliers (bottom center left). So do I take them out? Look at what happens when I overlay more groups:
Now I'm up to 11-3 shot groups. Lost another shot somewhere (again) so it becomes a 31 shot group. The important point here is that the shots that looked like fliers are not anymore. They are grouped so -- no flyers. By the way the light purple circle is not an MOA or inch measurement, it is SD and CEP related. CEP (Circular Error Probable) is an excellent measure of accuracy and precision. I want more!
All the best,
JAS
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