As reloaders we like to know how fast our bullets come out the barrel. Once
chronographs became affordable and apparently functional, it did not take long before
a CHRONY F-1, their cheapest version, also came out to the range with me, occasionally.
The darn thing is a little bit of a pain. That’s primarily because its functionality
is sensitive, as a minimum to position, to sunlight. When all is well, we get the
rewards in feet per second. At least most of the time. However, may we not be too
naïve, because sometimes the number on the display appears just a little too good to
be true. At least on my CHRONYs it did.
Yes, CHRONYs. I’m on number 2. Murdered the first one, I did. Not out of hatred. It
was 2nd degree, when while firing my small Kahr 9mm offhand across the screens one shot
came in too low. It was instantly fatal. Number 2 has the same sensitivities. I don’t
even try until the sun is on it. Even then the “ERR1” message appears frustratingly
often. OK, nothing personal, but I do seem a little harsh on these measuring devices.
Because about 4 years ago I smacked Nr2 with a sabot that had separated from a .308 Win
load firing a 22cal bullet. That sabot impacted the edge of the screen, but apparently
did not affect function.
Then in late March 2023 an opportunity showed up. Buddy Jim from CA came to visit,
brought his 6.5 Creedmoor to try at distant targets, ranges not available near his home.
Oh yes, when shooting at longer distances knowing the exact muzzle velocity is indeed
very helpful. For that he brought his device, a ProChrono. We set that up in the
proper place, then set up my CHRONY directly behind it. When he fired 129gr Hornady
bullets, his ProChrono gave appropriate readings in the 2600 fps range. My CHRONY
showed something around 1200 fps, what I call stupid data. It happens. As the morning
went on and the sun climbed, the CHRONY awoke. But then each time it read about 50 to
70 fps less than the ProChrono. At that point I was ready to kill my CHRONY #2 also.
No 9mm was at hand to make it look like an accident. That was good. Because later it
became obvious that it was silly of me to expect dependable and repeatable results from
the type of chronograph that uses optical changes to capture bullet speed. Testing
continued. I fired my .260 Rem. with Hornady 140gr ELD-M bullets next. Now CHRONY and
ProChrono read within 10 fps of each other. Huh? Which one can be trusted, if any??
I kept the CHRONY for the time being. At least it should provide ballpark info.
Shortly after, I engaged in a Redhawk .44 Mag evaluation. There came strings of data
like 1065; 1056; 1065; 1254; 1039. Or 1000; 1445; 1076. I was convinced my ammo was
not that inconsistent, ignored the misfit readouts. Then came the optimistic result
seen above. And later also 3984. My CHRONY was apparently “high” on something. Now
I wish these speeds were real.
OK, maybe not. Can you imagine the recoil from a 240 grainer out of a revolver at
those velocities? I had enough, ordered a ProChrono that same afternoon. That may
have been a tad too emotional, too early.
Before my ProChrono arrived, another thought trickled in. Why not a further comparison
test in series with the CHRONY Master and MagnetoSpeed which reside in Steve’s possession.
He agreed. Here is the test setup →
Note the weight below the tripod to help avoid sudden winds from blowing the setup down.
That’s from experience.
First Steve shot his 26” R700 in .260 Rem, Berger bullets, with two different powders.
The data we gathered appears a little sobering. For his first 5 shots agreement between the
three devices varied from 2 to 40 fps. And one of the CHRONYs always indicated a faster speed
than the Magnetospeed, just not always the same CHRONY. Also no surprise that CHRONY F-1 had
2 stupid readings. For his next 5 shots the agreement worsened, ranging between 3 and 52 fps.
You can see all data in the table below.
Then Steve attached his Magnetospeed to my Tikka CTR, also in .260 Rem, firing Hornady 140 gr.
ELD-Ms. Agreement improved, from 1 to 13 fps between the 3 devices. Now such results I could
live with. Since I had it along, my TC in 30 Herrett also got a quick go, but without the
Magneto. The CHRONY Master had trouble with those 110 gr. Vmax bullets, giving us 4 out of 6
stupid readings. And are the CHRONY F-1 results real??
Some conclusions:
The CHRONY Master displayed the highest speed most of the time. Best, but by no means
consistent agreement was between the CHRONY Master and MagnetoSpeed. Worst agreement was
between the two CHRONYs.
All 3 had better agreement with the Hornady 140 gr. ELD-M bullet than the Sierra 130 gr.
Tipped Game King.
Five days later we were at it again. Now there were 4 measuring devices! Dan assisted by
adding his LabRadar to the test setup. Of the four devices, the LabRadar was by far the
easiest and fastest to set up. Also, by sitting 18” to the side of the barrel, there was
no functional interference from the two CHRONYs and their sky screens and support rods.
Plus, the unit was completely out of harm’s way.
Note that the test and setup took place in the same location, same time in the morning, same
target position, meaning basically very similar sunlight conditions.
First Steve tested two loads in his Tikka CTR in .260 Rem. Then my CTR in .260 Rem got on
the bench, firing 4 different loads. After that my Tikka T3 in .223 Rem provided a data
string. All of that is summarized in the second table, below.
Conclusions:
No erroneous (or stupid) readings occurred that morning. The CHRONO Master recorded the
highest speed for each of the 35 shots. Worst agreement of the measuring devices was
between the two CHRONYs, best between MagnetoSpeed and Labradar. Similarly, the agreement
between MagnetoSpeed and CHRONY F-1 can be called “good”. But that was for this day, this
test. The previous testing with (only) three devices did not reflect such good agreement.
Clearly though, the Labradar is a winner. Easiest to set up, and able to measure bullet
speed from any gun. The MagnetoSpeed is also independent of light conditions, but will not
work with a suppressor and most, if not all, handguns. Its attachment method is somewhat
Mickey Mouse, and will that interfere with the accuracy of a longer thinner barrel? It
holds true here as well: you get what you pay for.
Well, since it arrived, a few words about my new Pro Chrono. Yes, it is light sensitive.
To date, though, it has given believable readings well before sunlight hit it. I am not
sorry about that purchase.
In its literature they recommended ‘side shields’, to make the ambient light at the sensors
as consistent as possible. I made some, which was easy to do, and no big deal to install
each time. Now, many outings later, I’d say that the Pro Chrono sets up easier than the
Chrony, is sturdier. Its increased length also makes it easier to align with the target,
such that speed and accuracy get tested simultaneously. Which really means that I get a
reading on the first shot of the morning. That was at best 50-50 with the Chrony. We did
not run any more comparison tests. I like that Pro Chrono, will simply ‘take’ what it tells
me from now on – except for obvious stupid readings, of which there have been very few in
several hundred shots fired to date.
These days, with components often not available, and always expensive, I wish I would have
troubled myself in the past and set up that Chrony each time, and then recorded all data.
The Pro Chrono will see such employment.
