Garmin Xero C1 Pro Developers Menu / Measuring Distanced Tracked

[GunsNotPuns]

I only learned of this just yesterday and it might be some use.

On your Xero C1 Pro, scroll down to Settings and go to "About". Hit OK five times and it will present you with developer's options. One of them is "Show Distance Tracked". Click OK on it to enable it.

The Xero C1 Pro seems to be measuring velocity between 20 and 30 metres. I had a low of about 19.7 metres and about 27 metres at its longest measurement distance.

It's display only -- you'll see the distance number beside the shot total -- and I couldn't figure out a way to have that number saved to the unit as another variable. At least, it didn't show up when I exported my data as CSV.

Now, I'll leave it to smarter people than I, but I do wonder if this can get someone part of the way of calculating BC based on this additional data.

 

[I Dont Care About You]

BC is a measurement of drag or deceleration. One would need two velocity points a known distance apart in order to calculate BC. The data you are getting from the Xero is one velocity point at one distance. You have precisely half the data needed to calculate drag.

 

[GunsNotPuns]

I am aware of that. I'm presenting this with the question of whether one could statistically blend and extrapolate data to achieve the same result.

 

[prairie lover]

I wonder if it then back calculates the shown speeds to the muzzle. Or is it 20m out?

 

[I Dont Care About You]

I am aware of that. I'm presenting this with the question of whether one could statistically blend and extrapolate data to achieve the same result.

Ho do you extrapolate something you don't have? Either you have two points or you don't. Its kinda cut n dried.

 

[I Dont Care About You]

I wonder if it then back calculates the shown speeds to the muzzle. Or is it 20m out?

Thats an interesting question but to do that, the calculation would require the BC of the bullet in use.

The more important aspect is that with these kinds of chronographs, you will need to set your ballistic calculations so that the velocity matches the longer measurement distance.

 

[todbartell]

I wonder if it then back calculates the shown speeds to the muzzle. Or is it 20m out?

Garmin give you the muzzle velocity, I have run mine against the Labradar and the muzzle velocity are usually within 1 fps of each other

 

[I Dont Care About You]

Garmin give you the muzzle velocity, I have run mine against the Labradar and the muzzle velocity are usually within 1 fps of each other

How do you know the displayed velocity is at the muzzle? The system doesn't read the velocity at the muzzle and it doesn't know the BC of the bullet, thus it has no way of calculating the velocity at the muzzle. That it says "muzzle velocity" doesn't mean that is true. You are making a massive assumption somewhere.

 

[todbartell]

Well on the Labradar it shows velocity at the muzzle (v0) and I set my v1 at 4 yards, which will always be slower than v0

The v0 of the Labradar and the Xero muzzle velocity are basically the same.

 

[I Dont Care About You]

The bottom pic shows the answer. The LabRadar displays two velocity points, at 4 and 75 (yards I assume). That allows the software to calculate velocity back to the muzzle.

That you can also show the Xero produces essentially the same velocity suggests the Xero is doing the same thing, just not displaying it.

Hard data is always better than guessing and supposition.