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The Chronology of Chronos

3/30/2025

1 Comment

 
Disclaimer:
1.- The items analyzed here have NOT been sponsored in any way form or fashion.
They have been acquired over commercial channels under CCA's own resources.
No comment is made with the intention to endorse or deprecate a product.
These are our factual findings.
​YMMV
2.- This note is written from the POV of a gunsmith that needs solid information in the process of the development of a project.
An old FT competitor once said: "He who lives by the Chrono, will die by the Chrono" and that is true once you get out in the field and do actual shooting.
As important as chronos are to me when used as tools, they do NOT guide the philosophy of a tune, or the settings for a gun.
Always remember that the chrono is a tool, YOU are the one that needs to take the decisions for what to do with a specific rifle based upon the task at hand and the capabilities of said rifle.

A bit of history

I've been interested in ballistics for as long as I can remember, made my first "catapult" at around age 3, and had my first toy mortar for my 4th Xmas.
From there to the "Atomic Cannon", bow and arrows, BB gun, first Crosman Pellet gun, then onto RF, CF, and all the way to whatever you can think that can be shot from the shoulder.

And I have always been of a very "curious" nature. Dad used to call me the "Boy of the Why's"
(Now I am paying for all I did back then, but that is another story, ROFL!).

So, when an elder cousin that was already in Engineering school told me that ballistics was all about the projectiles' speed, I started looking for ways to measure it.
.
.
.
Without success.
Truth is that measuring fast phenomena is hard.

By the time I was in Engineering school, and my shooting interests had gone all the way into reloading and bullet making (both, by casting and by swaging), I needed something that gave me some reasonable idea of where we we were at.

Looking around for ideas, I came across a note by some European ballistician that talked about "tape breaking" chronographs. Some research through the University Library, and some actual letters sent over "the Pond" through postal services, returned an exorbitant offer for a device that would measure the speed of a bullet by setting two "gates" (really just pieces of tape that were metal zig-zag strips sandwiched between cellophane tape) at a known distance apart and using an electronic chronometer to measure the time it took the projectile to travel between the two "gates".
Back then (1974-1975), the best electronic "stop watches" we could get were in the MHz region (about 1 million cycles per second), and those were expensive.
BUT, the oscilloscope of the lab was capable of much faster readings. Problem was that it needed a 120V outlet.
And, so, after making an experiment at the lab (with my old Crosman) and ascertaining that it was useful, I splurged the equivalent of US$125 in a battery driven Chrono that would have a frequency of ¼ mHz (that is 250 kHz).
Spacing the "gates" by 4 feet, I could measure pretty good velocities., though the precision was not extremely good.
Let's assume I was checking on a Standard NATO cartridge, that has MV's of around 2,800 fps, that would mean that in 4 feet, the chrono would count 357 cycles.
BUT, for each "partial cycle" that got counted or not, the difference to the true MV would be of about 17 fps.

Good enough for developmental work, but far from ideal.

The MAIN issue however, was that each shot fired, required a walk in front of the firing line, which meant a cold line, and 3 minutes to reset the tapes.

So, to chrono just a string of 20 shots, took an hour.

I was happy to do it, believe me. I could talk about real numbers, with known errors, and that put me on equal footing with many writers and some technicians working in the official and commercial fields of ammo making.

Of course I dreamt about purchasing an Oehler 33, and then a 35, but life got in the way, and I would dedicate less time to developmental work and more to actual shooting till I graduated and came back from England.
By then, I had a solid job and could easily spend the nearly US$400 required, Competition Electronics was already a well established company and  the compact "light screen" chronos were a reality.
It took the world 14 years to actually get to the point where the "average Joe" could measure the velocity of his projectiles, and by 1988, I had ordered one that I received courtesy of a friend that had a friend with an address in NY.

I used it extensively and cherished every moment.

I still have it, and it still works!
Picture
It's two feet long, weighs two pounds and the screens are minute (about 2"X 4").
​Talk about the "pucker factor" of shooting through such a small window.
AND you had to keep at least 10 feet between the muzzle and the Chrono!
Picture
Get all the white lines aligned and make double sure that you are using the right LOS height.
;-)

I went through several of the black cardboard "markers", and the top difusers were easy to make from plastic paper used in pro drafting.

It served me well until 2010, when in a trip to the US I was able to get the "current generation", which boasted IR detection (a problem for spring-piston airgunners, as we will discuss later), and could use powered light screens, no more waiting for daylight to do the measurements, no more hoping for a day that was overcast "just right":
Picture
This one, of course, was used and abused for the following 13 years.
Problem is: that one stopped working!
Competition Electronics offered no viable solution, perhaps based on the fact that it was well over a decade old, they suggested getting another one.
:-|
Well, that does not fly with me too well, so I cast a research net and came across what was supposed to be the most accurate of the "amateur" models, and I got it:
Picture
Over the last two years it has proven reliable and useful. A peculiarity is that, when using the wires to feed the IR screens, the screens come closer to each other, and so a "spacer" was added to maintain the correct 12" of distance between the two screens in order to get accurate results.

For a while, all was well in the World, but then, the connection between the Chrono and the computer/phone stopped working. Tried a BUNCH of solutions. Different phones, tablets, reloading the app, etc. But to no avail.
After calling the Caldwell people and laying down the problem, they said "Yes, we know about it, but we don't have a way to update the app, Android has changed and we cannot do anything about it".
Supposedly, they were going to call when some remedy was available, but so far . . . . crickets.
The MAIN issue here is that this model was designed around the app. AND, without the app, there is no local memory, nor computational capabilities, so, if you want to record a string, you need to jot down all the numbers, one by one, then upload the data into your Excel and then do the number crunching.
Which I do.
If that is what needs to be done to get solid information about the performance of a rifle, so be it.

I've learned recently that Caldwell has launched a new model that has BlueTooth communications so, I will try to get them to do the right thing (take this one back even for a nominal amount in exchange of the "new" one), IF they do, I will edit this article.

The Caldwell was supposed to be a "portable" device. The chrono itself works with a 9V battery, that can be a rechargeable one, and the IR screens, work with a 6V battery pack made up of 4 X AA's, that can also be rechargeable.
For a while, the portability and the capacity to record each shot as I was shooting groups proved to be a great asset. The occasional "flyer" could be discarded or confirmed. AND this takes us to

The present

So, when the communications between the phones and the Caldwell stopped working, I got again on the research train, and found not one, but TWO interesting solutions, so let's take what I consider to be the less effective first:
Picture
This is the Nate Chrony. It attaches directly to any barrel that has ½"-20 UNF muzzle thread, and if your barrel does not have a threaded muzzle, then there are adaptors available.
It is 3D printed and works, not with an App, but over WiFi, as a web-based "facility".
It is small:
Picture
And light.
You can attach it to the rifle and you really do not feel too much the added weight or mass.
It DOES have memory at the Web page level, and it has sufficient computing power to calculate averages, extreme spreads and standard deviations, you can store up to 4 strings, LONG strings. And it has the capabilities to  graph the data.
It is a bit awkward that you cannot graph PAST data, but if you are ordered and systematic, you should not have a problem. Also the Standard Deviation is calculated as a population, when the correct statistical approach is to calculate it as a Sample Standard Deviation, which is what a string of shots is.
If you have other chronos that you need to interoperate with this one, it also has a "calibrating" function.
​
There are two things that it does not have and that, to me, make it less than useful:
1.- There is no way to "export" the data, nor the graph.
2.- It needs an external power source.
If your phone does not have AMPLE battery capacity to drive itself, the WiFi, and the Chrony, your chronoing sessions could be somewhat short.

The Nate Chrony offers a wide enough "channel"  to make sure that it is not sensitive to smoke (from airguns dieseling during the initial shots), or debris in the field.
Picture
It would be ideal if it was not saddled by the need of the external power source. AND if it could export the data in an easy to operate manner (like a .CSV file).

And so, we come to the one that TO ME is the most useful:
Picture
This is the "Qiu Feng" (pronounced "Chiu Fang"). As you can see, it is also small and light.
Th body is an aluminum casting , closed by two aluminum "faces" that are screwed shut by two very long screws.
It has enough memory for up to 100 shots, and stores it in reverse order (so, shot #1 is really the last shot taken).
It works in both units (SAE and Metric), it stores the pellet weight, and calculates Muzzle Energy.
It has an App, that works well with phones that have Android 12 and newer.
The app can "tell/talk" the measurements to you, if you do not want to be constantly looking at the phone or tablet.
The internal battery will hold well for several sessions of chronoing.
It does NOT perform any calculations, nor can it export the data stored through the app.
It also allows you to "calibrate" the readings if you need to interoperate with other chronos.
​
So, if this one does not graph nor calculate, why is it the most useful?
To ME, the calculations are not useful if they are not done in a mathematically correct way, so I have to repeat the calculations anyway.
AND, if I am disciplined and take 10 shot strings at different bullseyes, I can map the results of the memory to the resulting target. That saves a ton of time when doing the write-ups.
The "channel" it offers is much narrower than the NateChrony's, so for those spring-piston airgunners be aware that smoke is opaque to IR (reason why the CO2 is a greenhouse gas), and that using the Qiu Feng in a spring-piston airgun may require cleaning BOTH screens from soot and hydrocarbon condensation:
Picture
This last issue caused me severe heart and head-ache, but I have to say that the two people on the other side of the Pacific that are in charge, took care, answered my EMails and tried their best to help me, without their help, I would have ended up deeply disliking the device, and all through my own fault of not recognizing that not all spring-piston airguns are completely devoid of some dieseling.

The "Qiu Feng" seems to have been designed for the air tube over the barrel rifles, you WILL need some washers that are ½"  ID and 1 ¼" OD to properly space the chrono at your muzzle.

We've come a LONG way, Baby!

Over the years, the art and science of building better and more useful chronos has taken huge steps.
From the original Oehler 10:
Picture
To the 33:
Picture
And beyond.
We should be grateful that things have come down in size, weight and price.
Truly, the "golden age" is right now:
Picture
Keep well and shoot straight!



HM

1 Comment
RidgeRunner
4/13/2025 06:49:08

I am still at the Caldwell stage. Since I do not own a "smart" phone, I will likely be here for a while.

Reply



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    Hector Medina

    2012 US National WFTF Spring Piston Champion
    2012 WFTF Spring Piston Grand Prix Winner
    2013 World's WFTF Spring Piston 7th place
    2014 Texas State WFTF Piston Champion
    2014 World's WFTF Spring Piston 5th place.
    2015 Maine State Champion WFTF Piston
    2015 Massachusetts State Champion WFTF Piston
    2015 New York State Champion WFTF Piston
    2015 US National WFTF Piston 2nd Place
    2016 Canadian WFTF Piston Champion
    2016 Pyramyd Air Cup WFTF Piston 1st Place
    2017 US Nationals Open Piston 3rd Place
    2018 WFTC's Member of Team USA Champion Springers
    2018 WFTC's 4th place Veteran Springer
    2020 Puerto Rico GP Piston First Place
    2020 NC State Championships 1st Place Piston
    2022 Maryland State Champion WFTF 
    2022 WFTC's Italy Member of TEAM USA 2nd place Springers
    2022 WFTC's Italy
    2nd Place Veteran Springers
    2023 WFTC's South Africa Member TEAM USA 1st place Springers
    2023 WFTC's South Africa
    2nd Place Veteran Springers

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