Chronograph confusion

[AbitNutz]

I'm in the market for a chronograph. The problem is which one? Every review I read seems they're all great and they all suck. Oehler is out of the question but I read on Midway USA's sight about the Shooting Chrony, Pact, CED and RCBS. If you read the reviews, about 75% say they're the greatest thing on earth...the remaining 25% say they never worked right and wouldn't use it as a door stop....regardless of manufacture.

So which one? They're all about the same price...

[qajaq59]

I hope you can get some good answers to that question that go way into the fine details. Such as why they are great, or why they suck. I've been holding off buying one for the same reason that you mentioned.

[AbitNutz]

I swear it's just bizarre....one guy will say the build quality is wonderful....the next review says it looks like it was made in someone's garage. Just insert any chronograph name....
God I wish I could part with mega dollars for an Oehler.

[Dan Cash]

A friend has a PACT that he bought back in the early 80s. It works well, is consistent and repeatable. I have a Chrony that is about 7 years old. I don't use it that often but it works well, is consistent and repeatable. All of them are sensative to light and difusion and will work better if installed in a light box but not always practical. The more money you pay, the more stuff the machine will calculate. I am not interested is a lot of the advanced calculations or hooking up to a compputer so my little Chrony and a paper note book suite me fine. I think I paie $100.00.

[Edubya]

I have spent way too much money in shooting equipment over the years, but I did hold back on getting a chronograph. Like Dan Cash, I bought one of the least expensive chronies and am perfectly happy with it. I think a lot of the dis-satisfaction is due to the user's inabilities, or too high of expectations. I also feel that many people are putting out information that is not quiet factual, i.e., "I got 1000 fps measured velocity over the chronograph and had only a +/- of 5 fps variation in a ten shot group." I have gotten as low as a +/- 11 fps variation with mine, but that was with factory match bullet in my .22! I did that for a test to see if they were all that much better than the cheaper factory bullets. Well, the "match bullets" traveled at 25% slower and there was a 50% less variation of velocity.

Ultimately, a chronograph is not gonna be the make all, do all tool of measuring your velocity, just like your calipers or mic, the operator must follow some basic rules and he should get some basic measurements that he can work with. Do not expect your chronograph to read the same as your friends, even when you line them up where the same projectile is passing over the two of them consecutively.

EW

[zardoz]

Been very happy with my CE ProChrono Digital. It has an option for a remote, but found I really didn't need that for what I do.

I enter my strings of shots into an excel spreadsheet manually, with local temp, barometric pressure, and humidity. Also add all the pertinent details of the load, and any notes about accuracy, quirks, leading, and whatnot. There is a different sheet tab in the master workbook for each cartridge type.

The spreadsheet also calculates energy, momentum, and Taylor K.O. factor.

Big part of the enjoyment for myself, doing all the analysis after the shooting session.
Most interesting all the things one learns over time.

[Harter66]

I've had a Chrony the F1 I think about 3 years . It is the simplest most basic model avalible. It has given me some suprizing results ,almost every load is faster than advertised ,but it gives me the same readings every time so no complaints.

[montana_charlie]

I work with a load until it shoots the smallest group, so I don't care what the velocity is.
But, for a chance of having small groups at long range, the ES and SD need to be small.
To get those numbers is why I bought a chronograph and the F-1 Chrony will do it...if you add a simple switch.

I don't need to use it often, and it makes me feel better knowing I'm not 'ignoring' a real expensive toy.

CM

[Artful]

Well put me down for the cheap model - My chrony works just fine but I have discoverd a few things - must have same orientation - not tiltled up or down - should be about same distance from muzzle and not too close - If your shooting dawn or dusk you will experience problems - get one of the LED hockeypuck lights - mount on the diffuser with some sticky backed Velcro - problem solved - Also found that each chrono graph is similar but not identical to others it may be counting really fast but each one has a different beat buy a little - don't believe me take three chonographs line them up and shoot over the top of each and check the measurements - then for amusement change the order and do it again - let's see what you get.

[blikseme300]

I have the F1 Master Chrony. The remote display and the DIY remote control makes this unit perfect for my needs. I cast, reload & shoot pistol mostly.

When I got the Chrony I set it up in my back yard and used a .177 air rifle to get to know the unit. It picks up the round passing through the screens each time. Impressive.

Bliksem

[GeneT]

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

[Heavy lead]

friends don't let friends shoot through their chronograph

[Dennis Eugene]

my Chrony is probley 10 or 12 years old it is all I need, But if I were to buy another it would be the cheapest one I could find with a printer. That's what I really wish I had a printer. Dennis

[AzShooter]

friends don't let friends shoot through their chronograph

I've let friends shoot through my chrono, unfortunately instead of through the screens they have shot through the chrono.

No problem. The PACT that I have had a guarantee that even if hit with a bullet they would replace it for $30. It's been replaced twice in the 15 years I've had it.

I now have a cheap Chrony as well for a backup. Works well so no complaints here.

[AZ-Stew]

The Chrony's with printer (don't know the models offhand, but you can look them up) are good enough for most people's work. Sure, I wish I had bought one of Oehler's Personal Ballistic Lab setups 10 years ago when I could have, but I really don't need the kind of accuracy required for certifying my ammo to meet govermnet contract specs. +/- 10 or so fps from what I might measure with an Oehler will suit my purposes. I can get that much variation by changing the distance a few feet from the bench to the chronograph.

You do want to find a unit that places the display and electronics unit on your bench, rather than out in front of the muzzle. If you make a mistake, less is lost. A printer and computer cable is handy, too.

Regards,

Stew

[lwknight]

I'll take a stab. I think that a lot of people have problems with their chronographs because they don't understand exactly how they work.
If the sky is clear then there is no light going directly into the optics. Thats what the diffusers do. They catch light from angles and light up so the optics can detect the bullet passing.
If the sun is low, you will not likely get good results. They do not work well in the shade either.
You can use artificial light as long as it is even and not from a pinpoint source like a light bulb.
Shining a bright light onto the white ceiling will work and a florescent light will work if the lamp is longways with the bullet travel.
The rods on the side are simply guide rods and hold the diffusers also. Thats all they do.

There are those that will tell you that you get errors because the pickups are mal-adjusted. I say bunk! There are no adjustments on any chronographs that I have seen at Cabelas or the likes of other stores and mine as well.

And everyone knows all that I know about the chronies.

[Alex Hamilton]

I'm in the market for a chronograph. The problem is which one? Every review I read seems they're all great and they all suck. Oehler is out of the question but I read on Midway USA's sight about the Shooting Chrony, Pact, CED and RCBS. If you read the reviews, about 75% say they're the greatest thing on earth...the remaining 25% say they never worked right and wouldn't use it as a door stop....regardless of manufacture.

So which one? They're all about the same price...

I use an ancient Shooting Chrony Model F, which I think is at least 20 years old. I looks as it was made from bent sheets of metal, but it is a tool, not a thing of beaty and it works. It just reads the velocity, which I write down for each shot, then calculate average, standard deviation and extreeme spread on my computer. Last time I looked a more up to date model was avaliable for about $100. It belongs to one of my clubs, so it has been used by many and shot up through the screens a few times, but it still works.

It is quick and reliable way to sort out good loads from less good.

Alex

[Ed Gallop]

I like my Chrony F1 and most error problems are of my doing. However... I do have a problem with the shades blowing off. Considered cementing all the parts together but it would be too bulky to pack. As for consistency, it seems to be right on. It shows my reloads are much more consistent than factory loads. Ed.

[qajaq59]

No problem. The PACT that I have had a guarantee that even if hit with a bullet they would replace it for $30. It's been replaced twice in the 15 years I've had it. Hmmm, that's good to know. I wonder if any other brands do that?

[crabo]

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

Thanks,

[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.

http://i624.photobucket.com/albums/tt321/Whitespider8591/Crono1.jpg

http://i624.photobucket.com/albums/tt321/Whitespider8591/Crono2.jpg

[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

[Whitespider]

Just one more illustration.
We humans have gotten pretty good at building things within tight tolerances, but there ain’t nothin’ perfect. Sky screen sensor mount systems leave a lot to be desired in the precision department; which means expecting both sensors to be mounted absolutely perfectly is unrealistic. There is a “margin-of-error” that increases as the distance away from the sensors increases; keeping the bullet path as close (within reason) to the sensors as possible will minimize that error margin.

http://i624.photobucket.com/albums/tt321/Whitespider8591/chrono3.jpg

[lwknight]

OK, I took for granted that no one in their right mind would shoot a chronograph at a steep cockeyed angle. My bad. I tend to forget how ignorant some people can be.

As for the second illustration: You would have to bust the plastic apart to see if the sensors look to be aligned. Even how can anyone know if they are exactly just right.

There may be some chronographs out here that can get out of whack and be adjusted back but I'd bet that its a very small percentage.

[mike in co]

am i correct in the above diagram that you have one sensor tilted back, torwards the bullet ?


with the single mounting bar of the ohler35 the sensors are all on the same 2 planes.

yes you can tilt your shot, but only a gross angle will change the distance.......


and what you dont point out, is that if all the shots are taken from the same bent position, it aint a big deal, unless comparing to prior shooting data with a diff layout.


even the lowly pact that i hate has a single bar to mount the sensors on with alignment plates.


mike in co

[mike in co]

and ...

my "eyes"(sensors) are set down in a holder that has a rectangular window.....

do your drawings take this into account ?


what is the angle of misalaignment in your last diagram ?

[Whitespider]

Good lord gentlemen. My illustrations are purposely exaggerated for visual clarity.

C'mon, we're talking about a device that can measures speeds in excess of 4000 FPS (and does it in tenths-of-a-foot-per-second) by timing the bullet between two points as close as 18-inches with some units. How much error-of-angle do you think it takes?

Let's say we use the common 2-Ft screen spacing and a bullet traveling 2000-FPS, that bullet passes between the screens in .001 of-a-second. Now if we step the bullet up to 2100, the elapsed time becomes .000952380954... of-a-second (actually that number has been rounded off to 12 digits because it spans several dozen). That was for a bullet velocity change of 100-FPS at the 2000-FPS level, imagine how minuscule the time change would be at velocities over 3000-FPS. Now imagine a velocity change of 20-FPS. And now imagine just a tiny misalignment of the sky screens (whether by user setup or manufacturing) that results in an error of just .10 of-an-inch (.24 would be 1%) at the point where the bullet passes.

The sensors for my PACT are mounted in molded plastic housings, and than screwed to a welded steel bar; is that a picture of precision to you? So if we have a tiny bit of error in sensor mounting, and the user sets up so the bullet passes just a tiny bit closer to one sensor, AND the user sets up so the bullet isn't centered over both sensors....... Well now, just how much error do we have?

Granted, we'll never get our chrono set up perfectly, 'cause it ain't a perfect world. But if we take that little extra care to align the sensors with bullet path the best we can, and keep the bullet as close to the sensors as is reasonably possible, the margin of error can be reduced dramatically. After all, isn't everything about shooting also about precision, consistency and repeatability? We measure groups to .1, or even .01 of an inch; we measure bullet run out; measure powder charges to tenths of a grain; size our bullets to .001 inch; etc., etc., etc...... Why would we just haphazardly slap our sky screens out with a "that's close enough" attitude?

[mike in co]

my point is that in the two setups i have used, the spacing is fixed...firmly bolted in place.
my bench and target height are fairly fixed....i place the shooting window in line and at the same height frt and back........
again in most situations it will be one set of numbers in one session...so while slightly skewed so is the temp and the humidity...who do you know that records the humidity ?

nice pics, nice reminder to shooters.....but in a single session...i don,t see the issue. i dont see people intentionally shooting at skewed angles.

on the other hand if they do shoot that poorly, set up that poorly , then likely all is is done the same (poorly)and they will never notice the difference.

the lack of consistant muzzle to first screen distance is a bigger issue. with in an inch or so of the muzzle velocity drops can be measured. the ohler 3 screen with 2 foot spacing for a total of 4 feet shows large drops. so measure to the muzzle for consistant data. i use 10 feet for most on mine, but ocassionally have to move to 12 for belted magnums.

mike in co

[Larry Gibson]

mike in co

my point is that in the two setups i have used, the spacing is fixed...firmly bolted in place. my bench and target height are fairly fixed....i place the shooting window in line and at the same height frt and back........ again in most situations it will be one set of numbers in one session...so while slightly skewed so is the temp and the humidity

That is certain a very good methodology to follow. Consistency is the key, especially setting the screens close to the same distance from the muzzle (within a few inches at least).

...who do you know that records the humidity ?

I do and have for many years. I also record the temperature, and altitude.

nice pics, nice reminder to shooters.....but in a single session...i don,t see the issue. i dont see people intentionally shooting at skewed angles.

You're correct about it not being much of an issue in a single session. I have seen a lot of haphazzard chronograph set ups. In all my years chronographing and watching others do it I've seen very, very few who take the time to set the screens correctly at the same distance from the muzzle. The problem comes when they begin to compare data from day to day with different set ups. Worse is when they compare their chronograph readings with those of someone else's who is across the country without any knowledge of the setup and conditions the data was obtained under. This is when we get somewhat obscured reports of fast barrels or slow barrels, 200+ fps variations of the "same load", etc. Different set ups with different conditions using different guns are going to give different velocity readings. However, with the quality of most chronographs and consistent set ups the reading will be consistent within a normal variation range.

on the other hand if they do shoot that poorly, set up that poorly , then likely all is is done the same (poorly)and they will never notice the difference.

Ahmen.

the lack of consistant muzzle to first screen distance is a bigger issue. with in an inch or so of the muzzle velocity drops can be measured. the ohler 3 screen with 2 foot spacing for a total of 4 feet shows large drops. so measure to the muzzle for consistant data. i use 10 feet for most on mine, but ocassionally have to move to 12 for belted magnums.

I use 15 feet to the first screen with either my Oehler M35P or with the M43. I've also found that a difference of +/- 3" gives a low enough variation that the MA falls within the ES of several tests of the same load out of the same rifle.

Many do not realise what a large difference in fps a small difference of screen spacing can make either. I use a "reference rifle" and one specific lot of ammunition to test the set up every time I set the chronograph and screens up. The AV must fall within the expected variation range. If not the I recheck the set up and have always found something not set correctly when this happens. A decent .22LR rifle with a brick or two of .22LR match ammo will do fine for this and will last a long time with simple 10 shot test strings.

Lots of good points in this thread. Too bad the instructions for most chronographs do not emphasize a correct and consistent set up enough.

Larry Gibson

[lwknight]

Luckily, its not all that complicated to figure out if your 30-06 is shooting 2600 fps or 2900 fps and shooting from a solid rest at a target through the chrono is common practice because we like to test accuracy while speed testing the load as well.

Personally , I don't care about a 10 fps error. The last rifle load that I worked on had some spreads of 300 or so fps when I started and when I got enough powder in the case they (according to my non professional chrono) leveled out at 12 fps spread with less than 1/2" groups @ 100 yds.

So maybe I had imperfect sensor alignment from the factory but , who cares? It worked out great and the velocity was what it was expected to be at 2990 fps with a 150 grain bullet 10' from the barrel. I was using 58 grains W760 and standard LR primers. I later learned that magnum primers probably would have stabilized with 54 grains and given the same velocity.
Thats my next project.

For most of us that just want to know whats going on with our deer rifle loads , no special instructions are required to operate the chronograph.
If you are going pro and want to worry about micro minute details , you probably are bored with this thread anyway.

I just would hate to discourage anyone from getting a chronograph because they read how complex its operation is.

[Doby45]

I am confused.

[StarMetal]

Luckily, its not all that complicated to figure out if your 30-06 is shooting 2600 fps or 2900 fps and shooting from a solid rest at a target through the chrono is common practice because we like to test accuracy while speed testing the load as well.

Personally , I don't care about a 10 fps error. The last rifle load that I worked on had some spreads of 300 or so fps when I started and when I got enough powder in the case they (according to my non professional chrono) leveled out at 12 fps spread with less than 1/2" groups @ 100 yds.

So maybe I had imperfect sensor alignment from the factory but , who cares? It worked out great and the velocity was what it was expected to be at 2990 fps with a 150 grain bullet 10' from the barrel. I was using 58 grains W760 and standard LR primers. I later learned that magnum primers probably would have stabilized with 54 grains and given the same velocity.
Thats my next project.

For most of us that just want to know whats going on with our deer rifle loads , no special instructions are required to operate the chronograph.
If you are going pro and want to worry about micro minute details , you probably are bored with this thread anyway.

I just would hate to discourage anyone from getting a chronograph because they read how complex its operation is.

You hit the nail dead on the head. How many of us are working for some big company, NASA, the government....and our chronographs have to be accurate right down to the 1/16th of a foot per second?

If you have any sense about reloading, have the manuals, etc...you're know if you have a really bad reading. For one thing you're not going to beat the max loads in the books by 100's of feet per second and your rifle stay together. With technology today I think they all have a decent set out. I have been using the Pro Electronics for years and have never had a problem with it.

[mpmarty]

A man with one watch knows what time it is. A man with two watches is never sure. Same with Chronographs. I use an F1 master chrony and am quite happy with it.

[Larry Gibson]

That's true but the man with one watch that doesn't know how to set it correctly or tell time doesn't do to well with it though he may be as happy with it. It's all just a matter of how much accuracy or data one wants out of your equipment is all.

Some are happy with a simple chrony that will tell them within reason how fast the bullet is going regardless of the accuracy of the set up or use. That's all well and fine. Same those who are happy with a simple Lee TL'd bullet over "the load" of Red Dot. That makes them happy and all is well. Many are not satisfied with just a TL'd lee bullet over "the load" of Red Dot and want more out of their loads. No difference and nothing wrong with either approach or one in the middle as long as all understand the limitations of what they are doing and the data they are collecting. Going out and setting up a chronograph, regardless of make, without any consistency gives satisfactory data that is pertimant to that load at that time with that set up. Conversly going out and setting up the chronograph consistently every time and noting the other conditions that effect the ammo's performance then gives data that is viable in comparison with other data gotten at other times. That's all that's being said here. Not much need to criticise either method or those in between. Some are just stating and explaing how and why they do things with chronographs is all. That's the nice thing about our free country, isn't it?

Larry Gibson

[montana_charlie]

It's possible to get variations that are the result of 'angles' even if the testing occurs on the same day with the same chronograph setup.

Say a guy gets all setup and fires his hunting load for group, with iron sights, while also recording velocity.
Then, he mounts his scope with it's quick release, see-thru mount, and fires another string.

Now, assume his rear sensor is glued in at a slight angle as depicted in the second diagram.

Because of the scope height, the second string of shots passes two inches closer to the sensors than the first string did. A rear sensor angled forward will record a slower velocity for the second string.
It will continue to happen as long as the shooter continues to try both configurations and has ammunition to keep testing.

He will go home convinced that mounting a scope on his rifle reduces muzzle velocity...and he'll have the numbers to prove it.

When he posts here to ask how that can be possible, which one of us will even consider the possibility that his chronograph setup may be the problem?

CM

[Larry Gibson]

Wow Charlie, that's an aweful good chrony that can make that kind of distinction;-) , given the probable randon variation of the AV in back to back strings of the same ammo out of the same rifle. It always amazes me of the infinate amount of potential tests of theories promulgated on this board!

Larry Gibson

[AbitNutz]

I'm going to get the CED M2 with the infrared sky screens. The whole kit will run less than $300.00 and then all I need is a decent tripod to mount it on.

This thread has really driven home how important setting it up is.

After really reading, understanding, setting it up...all I have to do is figure which part I'm going to shoot first.

[lwknight]

Shoot the guide rods first , save the display for last.

[mike in co]

I'm going to get the CED M2 with the infrared sky screens. The whole kit will run less than $300.00 and then all I need is a decent tripod to mount it on.

This thread has really driven home how important setting it up is.

After really reading, understanding, setting it up...all I have to do is figure which part I'm going to shoot first.

a good choice sir....

[mike in co]

It's possible to get variations that are the result of 'angles' even if the testing occurs on the same day with the same chronograph setup.

Say a guy gets all setup and fires his hunting load for group, with iron sights, while also recording velocity.
Then, he mounts his scope with it's quick release, see-thru mount, and fires another string.

Now, assume his rear sensor is glued in at a slight angle as depicted in the second diagram.

Because of the scope height, the second string of shots passes two inches closer to the sensors than the first string did. A rear sensor angled forward will record a slower velocity for the second string.
It will continue to happen as long as the shooter continues to try both configurations and has ammunition to keep testing.

He will go home convinced that mounting a scope on his rifle reduces muzzle velocity...and he'll have the numbers to prove it.

When he posts here to ask how that can be possible, which one of us will even consider the possibility that his chronograph setup may be the problem?

CM

simple question:
can you tell me the brand name of the chron that allows you to position the sensor tilted ?
the bor cronoy's are can monted, the pact is beam mounted, the ohler is beam monted ???
what one allows one to do as you two have indicated...mount one tilted ??

mike in co
( my next statement will be: then dont buy that one)

[Whitespider]

...all I have to do is figure which part I'm going to shoot first.

:oops: Years ago I bought one of the first PACT model 1 chronographs. At the time, affordable chronographs were just becoming available, not a lot of people had them. But even the $199.oo was a lot of money for me at the time, and I spent another $50.oo or so for the tripod.

The bar, or beam, that the plastic housings mounted on was made from two lengths of square tube steel with three pieces of flat steel welded across them, keeping the tubes evenly separated. The tops of sensors housings mounted flush on top of the bars, with the body of the housings hanging between and below them. The original sky screens didn't have light defusers, or any provisions for them, which made getting the sensors lined up a royal pain-in-the-....

The "brain box" had an on/off switch on the back and two buttons on the front, a "review" and an "edit". To operate the unit you first turned it on and the display would scroll some information about PACT, software, etc. Next you needed to push both of the front buttons simultaneously to put the unit in "ready" mode.

I spent the first two weeks shooting every gun and load I had over the thing, and so did a lot of my shooting pals. One problem was that, without light defusers, and under certain light conditions, it was difficult to get consistent readings; you would have to keep moving the sensors closer and closer to the bullet path until it started working acceptably.

Well, about two weeks after I got the thing, one of my pals came out with a new .22-250 and asked if he could shoot it over my chrono, and I readily agreed because it was sill new and fun, and I liked showing-it-off. I get him all set up on the bench, making a big production of aligning the sensors, and he touches off the first round. He looks at the display and says, "didn't work."
"No problem", says I, and I step up and raise the sensors a bit.
He shoots again... "nothing" he says.
Well, we keep going through this, him shooting and telling me it ain't working and me raising the sensors, until...... his bullet smashes through the first sensor housing, slamming into the center post of the tripod, cutting it cleanly in half and than exploding the second sensor housing.

I wanted to cry... I surveyed the damage... the photo-eye in the first sensor had survived but the second was destroyed, and the tripod was history. As I'm picking up the pieces and putting stuff away I notice that I had turned the "box" on but had never bothered to push the font buttons and put the unit in "ready" mode.
:groner:

I don't recall what the replacement parts cost me, but it wasn't near as bad as I thought it would be, most of the cost is in the "brain", I even ordered extra parts.

Oh, and that wasn't the last time I called PACT for sky screen parts, I believe I've called them 4 times now... maybe 5 times.

[EMC45]

I just got a PACT PC2 over the weekend. It is an older model, it looks to be in excellent shape! My buddy MGD45 (member here) has a Chrony brand chrono and he is pleased with it. It is the little green one that folds up and it was about 75 bucks with dealer discount from Midway I believe. I got mine for a trade of cast and Jbullets!!!! Thanks Wallace!! It has the tripod, spacer bar, difusers, and of course the box, which gives Velocity, SD, ES, and a bunch of other functions that I am not sure of due to no manual.

[EMC45]

Got my manual from PACT yesterday...Can't wait to fire this thing up!