I'm seeking input for an "experimental design" based on shooter interests in comparison of multiple popular chronographs on the market. I've been planning this for a few months, and finally have the free time coming up before the end of the year to begin the experimentation, so I'm issuing "LAST CALL!!" for input towards the comparisons folks would like to see between these units.

I sort of stumbled into an opportunity where I have 6 different chronographs in my hands, and after some discussion with other shooters, there was sufficient interest to see these all compared side by side.

***Pausing here to acknowledge that the inherent variability in precision for all of these units makes it impossible to determine which unit is correct vs. incorrect, so this series of comparisons will be focused on consumer experience comparisons. These are all quality chronographs, so I fully expect to read velocities which represent the actual speed of my ammunition, but when each unit can only read to within +/-3 to +/-15fps of the true value, and knowing these units typically read within a few fps when reading the same shot, knowing which one is actually "correct" for a given shot isn't really possible. The comparisons will analyze other aspects of comparison between the units.***

***Also acknowledging, not all aspects of comparison can be performed for all of the units in consideration. For example, the MagnetoSpeed and ProChrony optical chronograph can't be evaluated in the same ways or for the same weapons as can be the radar based units.***

I have at hand:
+ ProChrono Digital
+ MagnetoSpeed V3
+ LabRadar V1
+ Garmin Xero C1
+ Caldwell VelociRadar
+ LabRadar LX

I intend to compare these units for the following aspects:

Reading Reliability:

• Distance side to side beside rifle
• Distance behind muzzle
• Angle relative to the barrel
• Trigger distance limitations (minimum clear distance)
• Reading reliability in various rifle mount positions
• Suppressed fire vs. non-suppressed (rimfire, pistol, & centerfire rifle)
• Sensitivity to picking up neighboring shots (trigger + filtering vs. capture vs. no trigger)
• Minimum velocity specification confirmation

Other Function Comparison:

• Consistency of results relative to the collective
• Battery life comparison
• Charge speed
• Battery drain over fixed time & # of shots
• Physical dimension comparison
• Mobile App features comparison
• BC calculation accuracy vs. proven/trued BC (for applicable units)
• Compare measured velocities when mounted to rifle vs. static position on ground (Garmin & LabRadar LX)

These experiments will largely start with 22LR to establish some baselines, then re-testing the established boundaries with larger and faster cartridges (and some slower). I will be able to compare utility of these units for:

• Rimfire Pistol & Rifle
• BB/Pellet Pistol & Rifle
• Centerfire Pistol & Rifle
• Suppressed vs. non-Suppressed Rimfire & Centerfire Pistol & Rifle
• Shotgun
• Archery

I intend to compare a 4 corner matrix of small vs. large cartridges and slow vs. fast cartridges to determine if bullet size and speed influences the capture reliability. Much of these comparisons will be done with only one or two units at the same time, in respect for the opportunity for signal interference or unintentional amplification by running multiple units at the same time.

Please let me know if you have any suggestions towards specific comparisons between these units.

OK,, you succeeded, my brain is officially fried!

Would you have access to a digital high speed camera to calibrate/verify speed numbers given by the chronographs? I know they are somewhat more precise than when the old man was throwing them against the wall because they were so inaccurate even for bow speeds but I see different readings from the 2 I have all the time when I am working up loads. And those were not in any way cheap!

Not currently. I have done foil triggers with high speed cameras in the past, but that's beyond the scope of interest for this set of experiments.

Here is why:

The ProChrono Digital lists +/-1% precision, +/-30fps on a 3000fps bullet. The MagnetoSpeed V3 is stated to have 99.5-99.9% accuracy, +/-0.5-0.1% precision, +/-15fps to as tight as +/-3fps to the true speed. The other 4 units, the LabRadar V1 and LX, Caldwell VelociRadar, and Garmin Xero C1, all have the same +/-0.1% accuracy, again, meaning they are expected to read to with +/-3fps of truth.

Given that, even if I did the leg work to capture the true bullet speed for comparison against each unit, the entirety of the test results would be completely coincidental, and no assurance to any other buyer of any other unit that if they bought and compared other units, they'd get the same ranking for "closeness to true speed." Even the units with the looser potential error could prove to be the closest to the true value for my individual units, and even testing multiple replicants of each unit would still be no guarantee that all of a given brand/model would always be tighter than the other brands/models. So ultimately, it's a lot of work to rent high speed cameras and set up foil triggers (which impede most of these units anyway unless placed sufficiently far downrange, which obfuscates the true MV), which simply would not prove anything of value about the relative performance of the units. At best, I could measure whether my individual units were falling within manufacturer specifications, or not.

I did fail to mention the origin of this experiment - the aspects for comparison I've listed here represent the summation of the achievable observations I can make for these units, based on discussions with other shooters and requests by shooters to incorporate aspects into the protocol. I was asked the first time to do this comparison on a whim during conversation at a match during the Spring this year when I mentioned to a few new shooters that I found myself owning 4 chronographs, a request which was subsequently repeated when I mentioned in passing with these shooters and a few others that I came to own 5 chronographs after I won a LabRadar LX at an ELR match in the Fall. In crowd sourcing aspects for comparison, I was offered a 6th Chronograph, the Caldwell, to be included in the project, and a shooter from Florida mailed me his unit.

As common talking points, specific advantages of magnetosensor and radar units over optical chronographs, the newer, smaller radars over the older, larger units, and the specific positional (axial displacement and lateral/radial displacement) and angular sensitivities of the new units vs. the old have been questioned ad nauseum by shooters, but I have seen no reports of actual results for any of these units. So those positional sensitivities were in my first draft of a proposed protocol. I was then requested to integrate archery equipment and shotshells, as well as integrating suppressed fire (since the LabRadar V1 users recognized the dependence upon inertial triggers for suppressed fire). I was also asked to experiment with low range velocity as well as "boundary range" velocities, as some users have noted the Xero will exclude shots from a string which defy the specific velocity ranges described in the menu. Needing a means to produce only 100fps or 250fps velocities, I've incorporated BB/Pellet rifles into the mix (which also typically have required inertial triggers for the old LabRadar V1), as I BELIEVE I can throttle speed with my pellet rifles to straddle purposefully above or purposefully below the respective limits of MOST of these units. I honestly have no idea what I can use to pitch a bullet only 20fps across the ProChrono - maybe I'll orient it vertically and drop something off of my roof through the screens?).

So all of these aspects of comparison have been either common topics of concern during conversations leading up to the development of this protocol, OR were specific requests by shooters who have responded to my threads like this one around the web to request aspects of interest to be included in the protocol.

The output, as I currently intend it to be, will be a structured forum post as well as photo and video narratives (likely hosted on youtube, as currently planned) to provide reference for shooters who are considering purchase of any or all of these units.

For your 20 feet per second test, as you said, set up your optical chrono vertically and place a lamp directionally across the sensors. Take a 150grain bullet at around 6.2 feet from the first sensor and drop. If my math is correct (and I damn sure wouldn't take that as a given) the bullet should reach 20fps in between the sensors.

The MagnetoSpeed V3 and the Garmin Xero C1 Pro are the 2 I have. Dad used Chrony's for Bow primarily. He used published data for his reloading speeds since his primary concern with reloads was grouping accuracy. Not to mention they really didn't have all these fancy whoopdi doos when he was still with us. Light sensor only.

Oh, I'm fairly certain you know this already but in the slight chance you have never heard this, try your best to go through the center of your light sensor chrono's. High or low across the sensors will indeed cause variations. Significant ones. I have noted some as much as 60fps variance between a center crossing and a low crossing. Also, hitting the chrony is bad juju. Lets not discuss how I know this.

I may have opportunity to add an acoustic unit which claims +/-0.02% precision, +/-1fps, although the set up is a bit challenging. But if this delivers as promised, it would have 3x tighter resolution than any of the other units - BUT... It would remain to be simple coincidence whether my individual units are closer or farther from truth than one another.

Shot Position Sensitivity is one of the aspects of comparison for the optical chronograph. For what it's worth, the optical sensor types have the worst resolution for precision, +/-1%, so for a 3000fps cartridge, 1% being 30fps, 60fps variance would be right on the specification standard. Not very compelling.

Whew, I'm dizzy from all the things you want to test for. I can't wait to see they results!