In this Article:
Before we look at chronographs, a definition is in order…
Wikipedia defines “chronos” as time, from the ancient Greeks. If you Google “chronograph”, you will see not only our gun chronographs but also some very expensive wrist time pieces. So, we are talking about time in general and elapsed time to be more specific.
Time, I hear you say…what’s that got to do with chronographs? Why on earth would I need a chronograph? My loads are accurate enough for me. I hear this from time to time. Accurate enough? Accurate enough for what purpose? Punching holes in tin cans at 15 yards or nailing a big whitetail at 125 yards? Sure, the load used in the first example may not up to the task of the second, but without a chronograph, you may never know without actually posting targets at both those ranges and doing some shooting. The “chronos” factor has a lot to do with finding accurate loads. It can save you a lot of walking back and forth, putting up targets at hundred-yard clips. Remember, a chronograph is a very fancy type of stopwatch – it measures time – and that can help you a lot as a shooter. Here’s how it can help…
How A Chronograph Helps
How in the world can a chronograph tell you if the first example’s load above might work to nail that deer in the second without putting targets up at a full 125 yards? Simple – by looking at three calculations that a chronograph may provide or can easily be figured. Those numbers are:
Velocity. The chronograph’s main function is to tell you how fast your bullet (or arrow, shot charge, air soft pellet, etc.) is moving. Once you know the velocity, then the following two are easily figured. Some chronographs will do the figuring for you.
Standard Deviation. The standard deviation (SD) is a statistical measurement of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the values are spread out over a wider range. In terms of ballistics, a smaller SD usually equals an accurate load.
Extreme Spread. The extreme spread (ES) is simply the distance between the lowest and highest velocity. So, as an example, if your loads chronograph with the lowest velocity being 1000 and the highest being 1086, the ES would be 86. As with the SD, a smaller ES tends to result in a more accurate load, although this is not a rule carved into rock…I’ve had some loads with a high ES print small groups on paper but by and large, you want a smaller number here.
If the SD and ES are low, then that load is worth exploring. It might serve you well to go ahead and put out your 125-yard target for a true shooting test. But, if the numbers are large, you might want to try a different load. How does a chronograph tell us these things? Most new chronographs will figure these three calculations for you and display them either on the chrono’s screen or on a phone, tablet, etc. Let’s look at how a chronograph works.
How A Chronograph Works
Before going further, let’s make a limitation…we will look only at hobby-level chronographs. The top-end instruments that the bullet and cartridge makers use would be overkill for our needs, even if we could afford them. So, we will look at portable chronographs that use some sort of sky screens that are meant to be placed below the bullet’s path, and which cost under $600.
In simplest terms, a chronograph measures the time generated when a projectile crosses the first (clock-starting) optical sensor and then goes over the last (clock-stopping) optical sensor. These sensors are below the shooting-area-defining areas (usually marked by the use of a diffuser strip and rods-shoot through the opening). They generate the projectile’s velocity based on the bullet’s shadow passing over them. (Some chronographs use three sensors, but two is more common). The resultant time is converted to feet or meters per second (usually user-selectable) and is displayed on a screen. The display screen could be on the front of the all-in-one chronograph unit itself or on the chronograph’s receiver connected to the diffusers/shooting area by cabling. The advantage of the remotely-placed chrono unit is that, if you miss and hit the sky screens, you won’t destroy your remotely-placed chronograph – just the sensing unit. Been there, done that…they’re tough, but not that tough. (Historical note: early chronographs had actual screens of copper mesh or other material the bullet was shot through. Modern technology has graduated to optical sensors, so screens don’t have to be physically replaced after every shot). This is a very simple description of a pretty complicated process, but the idea is fairly straightforward…start the clock with your bullet’s shadow + stop the clock = display the velocity.
Indoors Vs. Outdoors
Most all chronographs built today can be used indoors with artificial light and outdoors in natural lighting. If used indoors, the diffusers need to be in place. Some chronos even offer lighting systems for their sky screens in indoor lighting…it evens things out.
Outside lighting is best if it’s subdued, like a cloudy day…but not too dark. I’ve had screwy readings from mine when I tried to use it on a very dark day. You do need a little light, to be sure. One benefit is that, on a cloudy day, you may not need your diffusers. I’ve shot over my chronograph without diffusers in place for a few months now. However, the converse is true on a very sunny day. I would definitely use the diffusers and seek the shade of a tree or something…direct sunlight will usually cause an “err3” on mine – shadow (or lack of) error. Experiment with yours. You want your chronograph to be a useful tool that you use a lot. It won’t be, if you have to hunt your diffuser screens, phone-connection cable, a 9-volt battery, tripod…you get it. I leave mine on its dedicated tripod in the garage all the time and bring it in during the really cold months. That way, the battery is good to go whenever and I have everything I need right there.
A Couple Of Suggestions
I do have a couple of suggestions to make concerning the first three chronos we’re going to look at, or any chrono that has the “brains” and the sensors in one box. The two Caldwells and the Competition Electronics Pro Chrono DLX all have the chrono unit and sensors in one box. You have to point your gun just over the top of the actual chrono in order to get your velocities, SD, ES, etc. As mentioned elsewhere, I shot a chrono once…this is not uncommon. I just didn’t aim high enough. And, on the Caldwell unit I have now, one of my sons hit one of the diffuser rods, bending it. These are “occupational hazards” that go along with ownership of a chronograph, but something you can avoid.
The first suggestion involves “protecting” the chrono with something that will stop a bullet. I sometimes will put my chrono on a picnic table and then set up to where I can shoot over it in that lower position. The table allows me to put a large chunk of firewood in front of the unit so that if my aim is off, I put the bullet in a chunk of wood as opposed to a fairly expensive chronograph. You could use whatever you had on hand to protect the unit – it’s just a suggestion but one that has had its origin in me shooting a chronograph years ago. (The brand name of that unit was the “Shooting Chrony” – I don’t think they meant for me to actually do that…). It makes me have to get up and walk to the unit to read the velocities if I don’t have it connected to my phone via the cable, but that’s a small price to pay. Again, this is just a suggestion but one born out of necessity.
The second suggestion concerns bending a diffuser arm. If it’s a cloudy day, I leave the diffusers off. It seems to make no difference to the chronograph. Again, try this with your own unit…it may or may not work. It’s just something I saw on You Tube and decided to try. Diffuser rods are not hard to replace, but if they’re not mounted on the box, you won’t need to replace them if they are shot.
I have selected five chronographs to look at in more detail. They range in price from about $84 to $550. Let’s look at them. The links will take you to Amazon where you can read more about each one and check the reviews. The prices are Amazon’s and were accurate at the time of publication.
Caldwell Ballistic Precision Chronograph
I own one of these Caldwells – it is the second chrono I’ve owned. I am impressed with mine. It seems to be accurate (I don’t have anything to compare it to but it is consistent with itself), and it gets very good battery life. The only quibble I have is that it is very sensitive to light – I know, it’s supposed to be – but it seems that I get just as good results without the diffusers in place if it’s a cloudy day. It does allow, via a long cable, connection to a phone or tablet. With the app, you can have all the statistical heavy lifting done for you. It will read off the velocities, SD, ES and other results. I put together an Excel spreadsheet that does pretty much the same thing, so I seldom connect my phone to it. I just enter the velocities and it does the rest. Either way, it is very instructive to learn what you can from five or more velocities. As stated above, the ES and SD are the really interesting numbers…it is from these that you really know if a load is worth pursuing, either factory or handload. The Caldwell Ballistic Precision is the starter-level chrono from Caldwell, but it seems to work just fine. I like the fact that the display is large and easy to read from my shooting position. The on/off switch allows you to go to yards or metric, depending on which way you push it…towards the front, yards and towards the rear, meters. It’s a solid performer for the money.
An interesting thing happens when you point a camera’s flash at a chronograph…it tries to measure the light’s speed…
Competition Electronics Pro Chrono DLX Chronograph
I would like to try the Competition Electronics Pro Chrono DLX. It is enough like my Caldwell that I would be familiar with it. One feature this chrono has, though, that my Caldwell doesn’t is BlueTooth. Find the chrono with your phone or tablet, connect the two then let the app do the hard work for you. No long, mini-plugged-cable to find and untangle…a wireless connection is so much handier.
The Pro Chrono DLX also utilizes a faster internal shot clock, which can aid in velocity accuracy and speed of computation. It is built a lot like the Caldwell above, with the on/off switch on the side, diffuser rod slots on top and a tripod mounting port on the bottom. This is definitely a step up from the Caldwell above. If you want to save a few bucks, you can get this same chrono without BlueTooth, but for the small price difference it doesn’t make sense to go that route. Competition Electronics has a good reputation with their chronographs and this one is no exception.
Caldwell Ballistic Precision Chronograph G2
Climbing up the Caldwell chroonograph tree, we come to the inverted Ballistic Precision G2. According to Caldwell, this unit is “Flipping Traditional Chronograph Technology Upside Down”. The first thing you notice about this unit is that it’s upside down. You shoot under the actual chronograph, in the area between the supporting rods and the base. In my opinion, that is a good thing: unlike the above units, the largest, most-open of the shooting area on this model is at the bottom, away from the unit itself. It uses an 18-inch sensor. You have more room for your bullet further away from the unit, unlike the others. This would be an advantage.
According to Caldwell, this unit is calibrated to +/- 0.25% of the true velocity. Its range is from 5 – 9999 f.p.s. I could see this one being well-adapted for indoor shooting, since the sensors point down and wouldn’t be affected by flickering fluorescent bulbs. In terms of connectivity, Bluetooth is built in. The app will record the usual data plus allow you to have it remember data logs, weather and other pertinent facts. You can then share that data over SMS (text). Another nice feature is that it uses a rechargeable lithium ion battery…no more hunting for 9-volt batteries when the one in the unit goes dead. And, if that isn’t enough, it’s got built-in LED sunscreen lighting for when conditions aren’t right at the range. This chronograph would make a good addition at either an indoor or an outdoor range. As our Aussie friends might say, Good On Ya, Caldwell!
LabRadar Ballistic Velocity Doppler Radar Chronograph
OK…I stretched the budget, fudged the numbers, to include this chronograph. As the Monty Python movie once so eloquently put it, “And Now For Something Completely Different.” This one is different.
Radar. Doppler Radar, to be specific. That’s how this little guy works. Developed by Infinition Inc of Quebec, this unit draws on their expertise in development of Doppler Radar technologies used by defense departments world-wide. This unit doesn’t rely on sky screens…it actually uses radar to track your bullet’s flight.
It will track your bullet’s flight…right out to 100 yards, with bullets that are large enough. (.17 and .20 caliber bullets have a tougher time being tracked). So, you can get multiple velocities for your single projectile out to that 100-yard range. This would be a very good thing for hunters and competitive shooters, who need to figure bullet drop into their shooting dope. This unit measures velocities from 65 – 3900 f.p.s. It will also “remember” 9999 series of up to 100 shots each. It stores information on an SD card or USB, for later download. It is versatile – it figures high/low/average/ES/SD numbers. It will also calculate kinetic energy, and figure IPSC/IDPA power factors. It will not wash your dishes. It uses 6-AA batteries, the only thing I could remotely ding it for.
If you are looking at a chronograph that does NOT require sky screens, this one’s your huckleberry. You need NO screens with this…stick it on a tripod and point it at your target downrange. Stand beside it and shoot. Shoot again, up to 100 shots. Save the info for later download. That’s it! It doesn’t really like tiny bullets (think .17 HMR) or bullets moving faster than about 4,000 f.p.s. but for most of your shooting, this would be a really great chrono to have. I like it. A lot.
MagnetoSpeed V3 Ballistic Chronograph
Here’s another interesting chronograph. The MagnetoSpeed V3 does not use sky screens which makes it somewhat similar to the Labradar model above. There, the similarity ends. You have no screens – you simply attach the sensor to the muzzle of your rifle or handgun. And, in another nod to the non-traditional methods of measuring velocity, you would expect a company named “magnetospeed” to have something to do with magnets. They sure do – velocities are measured by electromagnetic sensors and then translated into feet-per-second-velocities.
It will attach to a barrel from ½” to 2” thick. This allows it to straddle muzzle brakes or suppressors. It is simplicity itself – the unit on the muzzle transmits data to the display, located up to 6 feet away from the muzzle. The steel “blast shield” makes sure the actual sensor doesn’t get hurt. It will figure velocities and related information and then save it to a Micro SD card for later uploading to whatever device you choose. You can save strings of shots. Place the display up to 6 feet away while shooting and then go to town with it. The bayonet sensor is light and extremely resistant to blast – one has been used on a .338 Lapua Magnum with no ill effect.
There is nothing to set up, in terms of conventional chronographs. No screens, no worry about lighting…just attach the muzzle sensor, set up the display and fire away. There’s even a Sporter model that costs less, if the price is an issue.
I like the idea of a truly-portable chronograph that you can have with you every time you shoot. I would use a chrono more often if it didn’t involve setting everything up. Simply stick the sensor on your muzzle, connect the display/”brain” and you’re good to go. There’s even a Picatinny rail adapter available if you need one. This is a great idea…it might get more shooters into the ballistics side of things rather than just putting bullets downrange. I like this one, too.
To Sum Up
Every serious shooter needs a chronograph. The information gleaned from my forays with the chronos I’ve owned has helped my shooting. A more informed shooter is a better shooter, to be sure. If you know for a fact that the load you’ve just put together for hunting travels at an average velocity of XXX f.p.s., then you can figure energy, bullet drop and other terminal ballistics. This is information that is like money in the bank for the serious shooter. (And, don’t think that chronographs are only used to measure rifle velocities…mine has measured many more handgun bullets than rifle).
If you want to be a better shooter, consider getting a chronograph. These are not the only decent buys to be had in this field, but they are surely good values for the dollar. I can speak from experience with the first one listed…I like my Caldwell. Whether you go that way or another, maybe it’s about time…yup, about time, elapsed time. That’s what chronographs do…why not give one a try? Let us know below about your experiences with chronographs and any other comments you may have. As always, thanks for stopping by – now, go shooting but stay safe!