Chronograph confusion

[AzShooter]

RTFM

They are easy to set up. Just put the Chrony 9 ft in front of your bench. Make sure you put a target up about 6 inches over the Chrony so you don't end up shooting it.

Bring the instructions with you. They do so much more than just give you a readout of the speed but you can always just right the data down and then do the math at home.

[montana_charlie]

I bought a used Chrony, but have never used it. Any suggestions for proper setup and use?

Yes.
Go to their website and download the manual.
http://www.shootingchrony.com/

[Alex Hamilton]

I bought a used Chrony, but have never used it. Any suggestions for proper setup and use?
Thanks,

Assemble the chronograph as per my picture in earlier message. If it is a sunny day with clear blue sky you will also need the difuser screens and it does not harm to have them even on a cloudy day. Place the Chrony 12 feet from the muzzle on suitable stand. I use a photographic tripod. Line up the "holes" so that you can confortably shoot through them whilst on aim at the target. Switch on and fire away. Rest your handgun or rifle if you are testing for groups and fire away.
The chrony will show bullet velocity in feet per second in the window on the front panel.

Write down the velocity for each shot. When you get home find the Spreadsheet or Calculator on your computer and work out:-
a) average velocity
b) highest velocity
c) lowest velocity
d) extreme spread = b-c
e) standard deviation

Obviously, the smallest standard deviation and extreme spread the more consistend and potentially more accurate the load is, provided the bullet is of good quality. You can observe each shot on the target to get an idea where shot (b) and (c) hit. Average velocity is important so that you can keep well away from Transonic Stage which is close on either side of the speed of sound. If bullets start supersonic and go subsonic on the way to the target accuracy will not be at its best. Low Standard Deviation is also an indication that the powders is burning consistently.

Good shooting,

Alex

[mike in co]

I have two chronographs now, and have had as many as five. Of the currently available chrono's the only one I have not thoroughly tested is the CED. For my money the Oehler is the only thing going. The Pact is pretty good, but if you're relying on it (need to make PF in IPSC or similar) you should consider it about 10fps optimistic. The Oehler is very consistent in any light in which it registers.

Pact and Oehler have compatible screens. In my experience the Oehler screens are more robust. If you buy a Pact or Oehler chrono, the various flavors are identical in terms of velocity measurement - it's only the bells and whistles (like printing, software, etc) that change. The cheapest Pact is as accurate as the most expensive Pact - same with Oehler.

Chrony's are decent, but more finicky about lighting, more variable, and of course you're putting the whole brain under the bullet path, where your friend WILL shoot it...

GsT

except an ohler has three screens...and will tell you when a shot is suspect.....no one else does.
they build the industry stanard lab chono's.....

older technology....the ce with three screens would be nice..

[Freischütz]

I have an Oehler M33 that I bought in the mid-70s. It uses six D size batteries for power. To use the newer type of skyscreens, it was rebuilt in 1986. I believe the low cost of current machines and improvements in skyscreens really made chronographs usable.

I don't remember the exact cost, but I think my M33 was about $300. That was a lot of money (required spousal approval).

Once acquired, the fun of aligning the screens and dealing with light conditions began. “Iwknight”described the lighting problems nicely. There were no diffusers or side plates to reduce lighting issues or define the shooting area. Originally I aligned the screens by sticking cardboard in the light openings. The cardboard acted as front and rear sights. Once everything was aligned I removed the cardboard and had to be very careful to always position my rifle in the same place for each shot. Otherwise the bullet would not pass over both skyscreens. Later I taped pieces of copper wire to each side of the screens. The wires were six inches taller than the screens. That gave me a little open topped tunnel to shoot through. The tunnel was pretty narrow so gun-screen-target alignment could be time consuming.

The modern screens solve many of these problems. They allow you to align the gun, screens, and target quickly. They define the area through which your shots must pass. And, they solve some of the lighting problems.

As to which system I'd buy today, I'd first ask myself how many shots I expect to chronograph each year. Here I can rent a range chronograph for $5.00. That may be all you need. If you still want your own, ask the range personnel how their machines hold up and what they hear other shooters say their personally owned models.

[Lloyd Smale]

your budget is the determing factor. I had two differnt chronys they work but arent that reliable. I know have a pact it cost quite a bit more and works better but it still isnt the chronograph my buddys oheler is .

[qajaq59]

Here I can rent a range chronograph for $5.00.

I wish I could do that because I only need it once in a while.

[largom]

Chronographs are like trucks, that's why you get different opinions from different folks. Some like Fords, some like Chevy's, and others like a Dodge. My advice would be to get the best one you can afford that gives the info you want.

I have a Pact that is now over 20 years old, it has a printer, calculates ES, SD, and a bunch of other things if you want it to. You can turn the printer off if desired. This unit will calculate bullet drop, knock down, energy and more. You can get IR screens to shoot indoors if you like. This unit will run off of a 9 volt battery or 110 volt house current. I have never had any problems do to quality with this chrono.
If you buy a unit with a printer, keep it away from the muzzle blast area of your bench, as the blase can viberate the cables and give false readings. I like my PACT a lot.

Larry

[Whitespider]

It depends on the intended purpose of owning a chronograph.

If you just want to know how fast your bullet is moving than buy the least expensive chrono you can find. Chances are, after the initial experimentation, you'll rarely use the thing. One of the "all-in-one" units a perfect for this because they normally fold up into a single, compact, easy to transport and store unit.

I you plan to use it for load development you'll want to step-up a bit and get one that performs some basic calculations and keeps basic information in memory. At the least you'll want one that keeps count of shots fired and calculates Average Velocity, Extreme Spread, Standard Deviation and/or Mean Average Deviation. You'll also want to be able to review and delete individual shots and than re-calculate; handy if you believe an "error" has occurred because you won't have to re-shoot the entire string to get accurate numbers. Having the "brain box" on the bench next to you is also a good idea; not only because you'll probably use it more which increases the chances of an accident, but because it's just handier than walking down range. Keeping a couple extra light sensors on hand is also a good idea.

If you're heavy into ballistics, mega-detailed record keeping, speed shooting and what-not you'll probably want one advanced functions such as a second channel, timers, printers, the ability to couple to a computer, the ability to store separate strings, etc.

I agree that most people that have "trouble" with a chrono don't fully understand how they work. A chronograph doesn't see the bullet, it sees the shadow created by the bullet. A bright sunny day is the worst possible lighting condition for a chrono, and the lower the sun sits in the sky the worse it gets; whereas a bright overcast day is almost the perfect condition. Errors can be caused by the sun "glinting" off the bullet (common with jacketed or gas checks), muzzle blast, smoke, even gas checks or bullet lube flying off. On a sunny day, just setting up under a tree when the wind is moving the leaves can cause false readings. On a clear sunny day I try to setup in solid shade and use light defusers; on a bright cloudy day I remove the defusers because the light is already defused by the clouds. One trick I've used often on sunny days is to spread a white bed sheet on the ground under the sensors and/or place another, smaller piece of bed sheet over the defusers and down to the sensors (like a small tent), using cloths pins to hold it in place.

Any chronograph will produce the most accurate numbers if the bullet passes directly above and centered over the sensors. Also, accuracy is increased by the bullet passing closer to the sensors. The best scenario is when the bullet passes over each sensor at the exact same close distance above and perfectly centered. Of course, this ain't a perfect world and compromises must be made, I point this information only. Still, the point is, how well you line up the sensors can make a difference in performance, accuracy and repeatability.

[montana_charlie]

Still, the point is, how well you line up the sensors can make a difference in performance, accuracy and repeatability.

I think this was the most important point made in this thread.

The more care you take in getting the chronograph properly positioned, the more reliable it is. That, and having a fresh battery available...
CM

[lwknight]

Exactly how do you line up the sensors?
You just shoot straight through the guide rods and under the diffusers.
What else is there to it?

[Paladin 56]

I have a CE ProChrono Digital and an Oehler 43.

The ProChrono is much easier to use but of course doesn't do what the 43 will do, but it's also way less money. It seems every time I use the ProChrono I get at least one bad shot, and sometimes two. Not a big deal now that I can expect it. It gives all the basics and otherwise works great and set up couldn't be more simple.

Too bad Oehler no longer makes the Model 43, but they are coming out with a short run of the P35 again for those who may not be aware.

I think L W Knight says it best. Most people don't know how they work and end up blaming the equipment for lack of understanding/knowledge. I would be willing to guess the reason most chronos are shot (barring actual accidents such as the time I found out a quick detach scope mounted improperly dramatically changes the point of aim) is because a lot of people think the bullet has to be fractions of an inch above the screens. I've seen it done more than once. That and not taking sight height above bore into consideration.

I don't really think anyone make a bad unit. It's just what features and ease of use one has over the other that will fit ones needs.

[mike in co]

I don't really think anyone make a bad unit. It's just what features and ease of use one has over the other that will fit ones needs.

lol my pact spent more time in texas getting fixed than it ever did with me.......
i would never recomend a pact product, nor the relabled rcbs ones (?)( whoever bought them)

[10mmShooter]

Abitnutz

After reloading for twenty years, I just purchased my first chronograph about a month or so ago. I got a Chrony Beta Master from Midway for like $110. The only feedback I would give you is that a remote readout is very important. I purchased it to verify my loads because I'm considering shooting IDPA.

The Beta Master comes with a 16 ft cord allowing you to set the chrony up at a distance and still have the LCD readout and buttons at the bench with you.

My chrono does SD, spread, av etc and remembers the last 60 shots ....but you know what its really not needed because I write down each velocity then key it in Excel with I get home and I can do all the calculation for SD, enegry, spread AV back home. The one with a printer would be nice but add considerably to cost.

A few things you know about chrono and I'm going to generalize a bit.
1. Even when set up perfectly they will miss shots from time to time(deal with it)
2. When shooting outside they sensitive to the sun, so set up can be very important to capturing the most shots. Cloudy overcast days are perfect.
3. You should position the chrony as close to you as you can without having the muzzle blast interfere with the sensors. For me the manual said 5ft for pistols, I setup at 6 ft away and have no trouble(largest pistol I shoot is a 44, so a .500SW would need more distance as do rifles of course.) Even at 6 ft my chrono has some unburnt powder and bullet lube on the front, so you get the idea not too close.
4. Heres the biggie to get consistent reading and the least missed shots... get your shot right over the sensors and in the "window" that the chrono sensors have for my Beta Master the window is 4 inches tall and about 6 inches across kinda like an upside down trapaziod right over the top of chrono. So your shot placement is critical...the closer the chrono is to you the better you can aim your shots right over it. You must be precise ever time or you will shoot your chrono or the metal rods holding up the screens.( I shoot open sight pistols so not too big a deal..but a scoped rifle up close...if you arent careful you will have a $100 paper wieght. dont be fooled by the size of the sky screens they are way too large your target area is low at the bottom of the screens...again a small box 4x6 inch is where your shots need to go to be measured.

Hope this helps....some of the points I make can be cured by speading $300-$500 on a "fancy" chrono...but it my case, its just not needed, I pull the trigger the guns goes bang...the little LCD says 955 fps, I right it down...next shoot repeat. you get the idea.

[Paladin 56]

lol my pact spent more time in texas getting fixed than it ever did with me.......
i would never recomend a pact product, nor the relabled rcbs ones (?)( whoever bought them)

OK, how about everyone else who has never had a problem with their Pact product who I'm sure are in the vast majority? You can probably find someone who's had a problem with their Oehler and would never recommend them either.

Besides Pact, have you ever called customer service concerning a product? The few times I have, the trouble shooting starts with "there is a button on the front of the machine that says ON and OFF....." and goes from there. All of the most basic problems, most of which could have been rectified by simply reading the instructions, could have been solved prior to making the call.

I was referring to a company who just makes bad units not the once in a blue moon bad unit. The market won't allow them to stay in business.

David

[fredj338]

I have two chronographs now, and have had as many as five. Of the currently available chrono's the only one I have not thoroughly tested is the CED. For my money the Oehler is the only thing going. The Pact is pretty good, but if you're relying on it (need to make PF in IPSC or similar) you should consider it about 10fps optimistic. The Oehler is very consistent in any light in which it registers.

Pact and Oehler have compatible screens. In my experience the Oehler screens are more robust. If you buy a Pact or Oehler chrono, the various flavors are identical in terms of velocity measurement - it's only the bells and whistles (like printing, software, etc) that change. The cheapest Pact is as accurate as the most expensive Pact - same with Oehler.

Chrony's are decent, but more finicky about lighting, more variable, and of course you're putting the whole brain under the bullet path, where your friend WILL shoot it...

GsT

This is pretty much my exp. I Have an early PACT, had troubles w/ shot errors. I got fed up & bought an Oehler. It very rarely misses shots, as long is there is enough light to catch the bullets shadow. The CED is the model I would buy today. For the money, pretty darn good, far better than any of the cheap Chrony line.
The biggest problem w/ Chrony are the cheap screens. Regardless of how much you pay for one, they all use the same cheap screens. You have to shoot dead center (1" max either way is an error), no more than 6" above them to get readings. That is the primary reason they get shot so much. My friend & I lined up an Oehler, Chrony BM & CED. Shot them back to back to back w/ the same loads. All readings were within 8fps of each other. The Oehler never missed a shot, the CED less tha 5%, the Chrony, easily 40% of the shots were errors. We moved the screen units around so all modles were tested in all positions, same results.
If you value your time, I have to drive 3hrs to shoot o/ my chrono, then by the CED or pop for the limited prod Oehler (which I wouldn't, too pricey). Watch for sales, it's only like $60 more than the Chrony. If you just use your chrono for the occasional PF or checking the deer rig every year, get a cheap Chrony. You have been warned though, you do get what you pay for.

[Whitespider]

Exactly how do you line up the sensors?
You just shoot straight through the guide rods and under the diffusers.
What else is there to it?

A chronograph is a high-speed timer; when the first sensor “sees” the bullet it starts the timer, when the second sensor “sees” the bullet it stops the timer. The elapsed time is converted into FPS based on the distance between sensors (calibration). Consider these two examples; the gray area is what the sensors “see” and the red line is bullet path. Both are based on a three foot sensor spacing, or calibration.

The first example is side view and represents what happens when the bullet passes at different distances from the sensors. Notice that the bullet only travels 2.8 feet between the points where the first sensor “sees” it (starting the timer) and where the second sensor “sees” it (stopping the timer). This would result in the calculated FPS being displayed as faster than the actual speed of the bullet.

The second is looking down from above and represents what happens when the bullet path isn’t centered over the sensors. Now the bullet travels 3.2 feet, resulting in the calculated FPS being displayed as slower than the actual speed of the bullet.

[AbitNutz]

I found this review, it used very plain language. This is just the part where they talk about the Oehler. The entire page can be found at http://www.frfrogspad.com/ballisti.htm

I found it very helpful. After reading this and then going to the RSI home page at:

http://shootingsoftware.com/index.htm

I'm leaning toward the CED M2 with the infrared lighting option. There are some other "nice to have" options; carrying case, flat surface/table mount; rechargeable batteries and charger, etc. However, just those two items, with shipping, will likely bounce off $300.00. They highly recommend the infrared sky screens. I'm also likely to buy it from RSI as I've read that RSI has excellent customer support.

RSI sells what they call a "complete ballistics lab". This looks very comprehensive, software, hardware...likely well beyond my needs or interests.




A Note About the Oehler 35/35P

There are some folks out there who are seriously and maybe even obsessively hung up on the Oehler 35/35P chronographs (the 35P had a printer) even to the point of recommending that people should find and buy old 35s rather than newer units Before Oehler dropped it, the 35 series was a good chronograph in its day, but it is old technology and has been superceded by modern electronics in accuracy, stability, easier to use features including a large easy to read display, and functionality.

The CED Millenium II runs a 48 MHz chipset, not a 4.0 MHz. like the Oehler, which also used a lot of analog technology. Oehler's "proof screen" was more of a marketing ploy than a necessity as all it does is measure the velocity twice and cries "tilt if there is a specified discrepancy between the two. Bad shots are easily detected without the "proof screen."

Modern sensor technology used on the CED is way ahead of the original Oehler screens both in sensitivity, reading area and freedom from interference and they will work in a wider variation of lighting conditions than any other brand. In fact Oehler apparently modified their screen mechanical design to effectively duplicate the CED design for better field of view and lighting error handling. The CED also offers an optional battery powered true IR head set that works in complete darkness or conditions previously impossible to shoot under..

CED is now the official chronograph for all sanctioned handgun competitions from IPSC to SSAS. It has replaced the 35 due to it's ability to get consistent readings despite changing lighting conditions, especially when equipped with the IR head option.

With today's technology the 35P with its printer is even more of an anachronism since the use of non-volatile memory allows you to save the data from 500 strings (2000 shots) and to then download the data to your PC, to ShootingLab software, or to print it at home without the bother of lugging obsolete, battery sucking printer technology.

From a historical perspective Ken Oehler's 35 was the premier product of its day and deserved support but there is a time when one must recognize technology marches on and a product becomes obsolete. No longer in being in production might be a starting clue. Some still love the Studebaker as well but the appreciation should be historical. The Studebaker was a phenomenal car with pioneering technology but is no longer being made. Should one recommend a Studebaker over all other cars today?

If you own a 35, and it is working for you, and you don't need the features of a newer chronograph, run it until it quits. I would however, never suggest someone without a chronograph hunt for an old used 35. That's just over the top and analogous to telling someone to hunt for a Studebaker as their only car.

[montana_charlie]

Exactly how do you line up the sensors?
You just shoot straight through the guide rods and under the diffusers.
What else is there to it?

The first example is side view and represents what happens when the bullet passes at different distances from the sensors.

The second is looking down from above and represents what happens when the bullet path isn’t centered over the sensors.

That nicely illustrates the value of sensor alignment, Whitespider.
I sandbag my Sharps so it's sights are looking at the bullseye, then leave the breech open.
I do my 'sensor alignment' from the rear of the Chrony, and quit only when my eye is four inches above the sensors...and looking clear through the rifle's bore.

That way the sensors are parallel to the 'rainbow trajectory'...not the line of sight.

CM

[GeneT]

I found this review,
<snip>...
There are some folks out there who are seriously and maybe even obsessively hung up on the Oehler 35/35P chronographs (the 35P had a printer) even to the point of recommending that people should find and buy old 35s rather than newer units Before Oehler dropped it, the 35 series was a good chronograph in its day, but it is old technology and has been superceded by modern electronics in accuracy, stability, easier to use features including a large easy to read display, and functionality.

The CED Millenium II runs a 48 MHz chipset, not a 4.0 MHz. like the Oehler, which also used a lot of analog technology. Oehler's "proof screen" was more of a marketing ploy than a necessity as all it does is measure the velocity twice and cries "tilt if there is a specified discrepancy between the two. Bad shots are easily detected without the "proof screen."

Modern sensor technology used on the CED is way ahead of the original Oehler screens both in sensitivity, reading area and freedom from interference and they will work in a wider variation of lighting conditions than any other brand. In fact Oehler apparently modified their screen mechanical design to effectively duplicate the CED design for better field of view and lighting error handling. The CED also offers an optional battery powered true IR head set that works in complete darkness or conditions previously impossible to shoot under..

This is much more marketing than any kind of serious review. I won't bash the CED - it appears to be a decent machine, but the jabs he's poking at the old Oehler are just that - they are not anything that should be taken seriously. His comments about the speed of the chipset and analog technology are completely meaningless in terms of determining which chrono is better. With that sort of propaganda, I couldn't really take any of the 'review' seriously.

(That said, the CED is probably a fine choice - I certainly wouldn't hold out for something you may not find).

GsT