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Garmin Xero C1 Pro

Yep. As I had brought up early in this thread, your results are very similar to ours. LabRadar and Excel calculate SD for small groups as a small sample size, but Garmin calculates incorrectly, for a large population size. My second polite notification to Garmin a month ago regarding this issue with specifics has gone unanswered. Shame on them. Typical from my past experiences with Garmin.
 
fyi

Shot a NRL 22 match today where there were 2 Garmins to play with.

Bench mounted on tripod: easier than blowing your nose, worked every time (suppressed and non-suppressed), no interference from other rifles.

Weapon mounted: produced several erratic numbers but shooter was able to delete the bad numbers. Believe it is from the shock/vibration. Only a a very heavy .22lr so not sure how well this would work on a center fire. Will need to see as more people use them weapon mounted. Admittedly, Garmin does not say it is suited for weapon mounting. I recall the new LR being marketed as weapon mountable.
 
Anybody have any details on this new chrono?View attachment 498903View attachment 498904
Yep, used it for the first time last Monday. Easy to setup less than a minute as opposed to about 45-60 minutes for my old Caldwell, and it did not miss any shots or record any other shots of shooters at the range, just captured my shots. I liked it a lot. I am glad I waited and did not purchase the Lab Radar I was holding off from buying, although Lab Radar has now come out with a compact version. I am happy with what I got.
 
Yep. As I had brought up early in this thread, your results are very similar to ours. LabRadar and Excel calculate SD for small groups as a small sample size, but Garmin calculates incorrectly, for a large population size. My second polite notification to Garmin a month ago regarding this issue with specifics has gone unanswered. Shame on them. Typical from my past experiences with Garmin.
IHFarmer actually reported the opposite: that Labradar calculates as a sample from a large population, and Garmin calculates the entire small population. Which is it? I rewatched the video, and what I describe is what the guy in the video stated.
 
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IHFarmer actually reported the opposite: that Labradar calculates as a sample from a large population, and Garmin calculates as a small sample. Which is it?
Velocity is always a guesstimate if you're shooting at distance, that's why you have to true your ballistics calculator.
With all chronos, it's a starting point. 100-600 yards you only true velocity with a ballistics calculator, past 800 you true your BC and not velocity
 
I am a little perplexed with my garmin the last 2 days out shooting. I've only missed one shot I can remember in a couple hundred between bare muzzle, braked, and suppressed. Yesterday I was shooting my 27 Sherman mag and have done so before with no issues. It is braked. First of three rounds with a 170 Berger all picked up. Then I had a pressure test loaded with 175 sierra game changers and it didn't pick up any of the four shots. Never moved anything between any shots. Today did the same. Shot first three rounds with 170 bergers and all picked up. Then had one loaded with the 175 sierra gamechanger. Once again I moved nothing and it didn't pick it up. Shot 3 rounds after that with a braked 33 nosler and it picked all those up too. Anyone have any ideas why that would happen? The only change was the bullet but it won't pick those up. I tried a different relation from the garmin to the muzzle today vs the previous day.
 
IHFarmer actually reported the opposite: that Labradar calculates as a sample from a large population, and Garmin calculates as a small sample. Which is it?
I didn't find IHFarmer's post, but in another thread, we've discussed this Garmin SD issue extensively. Garmin calculates (an optimistic) SD for small sample sizes. Less than 20. For 3 shots, the SD from Garmin will always be too optimistic. For 50 shots, it will be correct. As an example, let's say your velocities are 2795, 2800 and 2805 fps. Excel's STDEVP (for a [large] population) would calculate SD to be about 4.1--this is what the Garmin we used always calculated. We'd put the raw velocities for three or five shot strings into Excel and we'd get an overly optimistic SD. What Garmin SHOULD do for small groups is use a function like Excel's STDEV. This is for small group sizes, and produces a SD of 5. When we did this test two months ago, we use my LabRadar and my friend's Garmin at the same time, and for both of our rifles. For both of our rifles and 10 groups of 3 shots each, we got similar velocities between devices, but his Garmin SD's were always better than my LabRadar's SD's. We took all of the velocities, ran them in Excel, and the Garmin used the wrong method--they use SDEVP. LabRadar and Excel do the calculations correctly, and agree for small populations. I've contacted Garmin twice about this, and never heard a word back.
 
It has been a few decades since I studied Engineering Statistics, but I do remember a few things. To be significant, you have to have a large population. To be "accurate" you have to use the "whole" population, Now I understand that Excel gives you the option to calculate SD on a Sample or on the Population. If you are using a "sample" then its not accurate. If you have a small population, it can be "accurate" but NOT not meaningful. I truly do not understand what the arguments for and against are here, Maybe I am just getting old. BTW, I do not have either Garmin nor LR. Just an old optical CED.
 
η ταν η επί τας
Has several meanings according to or which language or interpretation.
I will go with the Sparta/Greek!

May need to purchase the Lab Radar LX - Sparta

If going with the Dutch/English
Garmin Xero

Since we have several Chronographs including the new Garmin Xero and the good old reliable LR with many options for Ballistics

We may GO with the newer η ταν η επί τας!
 
η ταν η επί τας
Has several meanings according to or which language or interpretation.
I will go with the Sparta/Greek!

May need to purchase the Lab Radar LX - Sparta

If going with the Dutch/English
Garmin Xero

Since we have several Chronographs including the new Garmin Xero and the good old reliable LR with many options for Ballistics

We may GO with the newer η ταν η επί τας!
🤣 only one meaning for "η ταν η επί τας" It is written in the original language, for a reason. At least it is the only one I was taught in school. It is what the Spartan mother would say to the son about to go to war when she gave him his shield. Carry it back victoriously, or be carried back dead on it.
I just love it when people use a population of 5 to perform statistics. And I am NOT a statistician.
Back to Garmin vs. LR. I have no dog in this fight, I just love it that LR has its new version coming and I hope more come to market. Better for us all.
 
It has been a few decades since I studied Engineering Statistics, but I do remember a few things. To be significant, you have to have a large population. To be "accurate" you have to use the "whole" population, Now I understand that Excel gives you the option to calculate SD on a Sample or on the Population. If you are using a "sample" then its not accurate. If you have a small population, it can be "accurate" but NOT not meaningful. I truly do not understand what the arguments for and against are here, Maybe I am just getting old. BTW, I do not have either Garmin nor LR. Just an old optical CED.
Yep. You're spot on. By using a "sample", you're admitting that you don't have all the data from a normal population, and your SD should be worse. Some almost 50 years now since my statistics class in college, I still have occasional dreams that I'm going to my statistics final exam, but forgot to go to class or study all quarter. Never had those bad dreams with engineering classes....
 
Yep. As I had brought up early in this thread, your results are very similar to ours. LabRadar and Excel calculate SD for small groups as a small sample size, but Garmin calculates incorrectly, for a large population size. My second polite notification to Garmin a month ago regarding this issue with specifics has gone unanswered. Shame on them. Typical from my past experiences with Garmin.
I keep seeing the term "wrong" thrown around when it is pointed out that Garmin uses Population SD. Population SD and Sample SD are 2 different statistical metrics, either or both of which can be applied, depending on what is being examined and what is trying to be learned. Calling one of them wrong is not accurate; they are different.

Population SD gives the SD of the specific set of data.

Sample SD uses a group of data, presumably as a sample from a larger data set, and uses the SD of the sample set to estimate the expected SD of the full data set.

Two different tools, two different output values, two different purposes. Neither are wrong.


Now having said that, you can't compare a Sample SD value to a Population SD value. If you have LR data and want to compare it to Garmin data, you can't. They are different metrics with different relevant values. Different, not wrong.

And no one should be comparing any internally-generated SD values from any black box device like LR, Xero, ManetoSpeed, etc. to a different device. There are too many potential unseen issues like rounding, truncation, etc, that will cause differences in the output values even if the same root equation is being used. If you want to compare across platforms, the only proper way is to enter the raw data into Excel or some other format where the same equations and calculation standards are used on all data sets. Only then can an actual comparison be done.
 
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I keep seeing the term "wrong" thrown around when it is pointed out that Garmin uses Population SD. Population SD and Sample SD are 2 different statistical metrics, either or both of which can be applied, depending on what is being examined and what is trying to be learned. Calling one of them wrong is not accurate; they are different.

Population SD gives the SD of the specific set of data.

Sample SD uses a group of data, presumably as a sample from a larger data set, and uses the SD of the sample set to estimate the expected SD of the full data set.

Two different tools, two different output values, two different purposes. Neither are wrong.


Now having said that, you can't compare a Sample SD value to a Population SD value. If you have LR data and want to compare it to Garmin data, you can't. They are different metrics with different relevant values. Different, not wrong.

And no one should be comparing any internally-generated SD values from any black box device like LR, Xero, ManetoSpeed, etc. to a different device. There are too many potential unseen issues like rounding, truncation, etc, that will cause differences in the output values even if the same root equation is being used. If you want to compare across platforms, the only proper way is to enter the raw data into Excel or some other format where the same equations and calculation standards are used on all data sets. Only then can an actual comparison be done.
I beg to differ. Garmin calculates it WRONG. First, we're assuming a normal (bell-shaped) distribution. Not a bimodal, triangular, square top distribution, etc. Most of us are shooting smaller samples of data, well under 30, and more likely 5 to 10 shots looking for an average velocity, ES and SD. If one uses the sample SD calculations for smaller samples, (Excel: STDEV) the denominator is sqrt(N-1). For a population, that denominator is sqrt(N). This has a huge effect for the shooter doing small groups. What is worth noting is that as the sample size gets larger and larger towards the "population", the results from STDEV and STDEVP (sample and population) converge with minimal error. Since Garmin doesn't state their method, but uses a population calculation, this is inherently the wrong way to do it. The correct way to do it is to use a Sample SD and let it converge for larger sample sizes or full populations of data. The difference for a set of 30 data points is typically about 0.1 difference in SD between the two methods.
Also, we did use Excel with STDEV and STDEVP for raw data from LabRadar as well as Garmin, and we got identical results using STDEV vs LabRadar and STDEVP for Garmin.
 
I bought the Garmin to do gather velocity measurements to do load development. My closest range is an indoor range with 100 yard rifle bays and am limited setting up equipment in the bay. The Garmin sets up in less than a minute, is small and compact, isn't affected my shooters in the next bay, and picks up all my shots. It's a great little device and works well for me.
 
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