How do you track your cone of accuracy?

[gtriple]

Do you shoot the same target? Do overlay a new target over the original? Or is there a better way to calculate it?

 

[WKR]

I overlay targets and line them up to have the same POA if that makes sense.
But im interested to see if there is a better way or maybe some software that can do it for you.

I use the BallisticX app and I wonder if the premium version has that option.

 

[gtriple]

I overlay targets and line them up to have the same POA if that makes sense.
But im interested to see if there is a better way or maybe some software that can do it for you.

I use the BallisticX app and I wonder if the premium version has that option.

That's what I've been starting to do. But I've also tried to figure out a way to calculate it just to remove the potential user error with lining up the targets. My best guess at a COA calculation is to take the maximum Elevation/Windage distance, use the Pythagorean theorem, then double it.

COA = sqrt(E^2 + W^2) * 2

The only issue I've found with that is if you adjust your zero.

 

[solarshooter]

The simplest way is to fire a large number of shots (10-30) into a single target/aim point and measure the extreme size. You lose insight into the distribution of the shots inside the group, but you are getting a statistically meaningful measurement of your rifle's true accuracy cone.

Next simplest is one of the apps that allows you to take a photo of the group and measure it's size. The only downside with some of these is you have to manually place every shot, and it can be difficult to overlay separate targets without manual processing of this data (see next option).

My personally preferred method is to shoot groups of 3-5, and then manually measure x/y coordinates of each shot relative to point of aim. I input this data in excel, and then I can overlay it and do a variety of other things with it. This is obviously more work, but it doesn't take too long (10-15mins for 30 shots), and it offers a few big benefits:

• You can precisely calculate your true zero.
• You can continually add shots/groups to this list, increasing the sample size over time.
• Mean and standard deviation of radius are more meaningful metrics than group size, since you're getting information from every single shot rather than just two shots per group. This actually allows you to get a more accurate measurement of your rifle's accuracy in fewer shots.
• You can statistically compare two different loads (t-test) to evaluate differences in a rigorous way
• For me, digital records will last longer, and I can reference them on my computer/phone/a friends phone anywhere I have a cell signal. I already maintain all my reloading, muzzle velocity, and group size data in excel, so this is an easy extension of that practice.