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Old August 18, 2011, 12:27 PM   #1
dunerjeff
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Good chronographs

Which chronographs have been most reliable?I know some are fussy with bullet sizes or lower velosities,but I'd like to get some opinions from people that own them before I go that route. Most of my uses will be for pistols, but from time to time I'd like to chrono some rifles(it would most likely be .20 cal).And yes a remote would be ideal.
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Old August 18, 2011, 12:51 PM   #2
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I've got a Chrony Master that I like a lot. If I start getting errors, it's normally the battery. I keep a new, hot spare battery in the box that holds the chronograph and installing the new battery normally sets things straight.
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Old August 18, 2011, 12:57 PM   #3
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what makes chronographs give funny readings is light conditions , having the muzzle to close to the front screen and weak batteries. out of a 22-250 I have got reliable readings up to 4,000 fps so light and shiny bullets in my opinion have nothing to do with bad readings. I have an Oehler 33 that I paid $300 for but that was the only game in town 25 years ago. I don't know much about the new ones since I don't have a reason to look at them. one thing to keep in mind is that the worst I can do with mine is shoot a screen. on most of the new ones today a mistake will blow up the brains and all which means a new chronograph.
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Old August 18, 2011, 01:19 PM   #4
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I have a Chrony Master and it works. Working it seems archaic for the computer age. If I don't have the instructions with me, I'm screwed! crs
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Old August 18, 2011, 01:39 PM   #5
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The old Oehler 35P was considered the gold standard and the CED Millennium and its successor, the CED M2, both agree with it extremely closely. I own both of the first two and am able to use them in tandem spaced a known distance to derive real ballistic coefficients. In his book, Applied Ballistics for Long Range Shooting, Bryan Litz says he got the same result comparing the Oehler and CED. They are within a few fps of one another, and well within shot-to-shot differences.

CED has a good write-up of the many different factors than can mess up chronograph readings. A couple of them apply only to their units, but most apply to all. Move the scroll bar down half way on this page and look for a heading called "Variables that will effect results are as follows:" and read the numbered items under it.
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Old August 18, 2011, 04:34 PM   #6
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hitting a screen was another question I forgot to ask.Though not likely,I'd definately wouldn't want to scrap the thing out for a mistake.Oehlers was the one I had looked at though it was more than the Chrony Master.Thats the dillema ,the Chrony Mater seems like a good deal,especialy when I'm not planning on using it day in-day out for years,but the second or third time out I could hit the screens and ,well I won't hopefully. The tandem sounds good for bullets that you can't find BC info on,like all the Berry's I shoot.Being able to do all your shooting and then go home and record all the data then, instead of having to do it at the range would be nice also(M2).Thanks for the info.
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Old August 18, 2011, 05:04 PM   #7
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I have a CED works fine. I like having the readout and controls on the bench
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Old August 18, 2011, 05:33 PM   #8
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Midway has a bunch of brands and looking at the reveiws, every single one is either the best and works great or junk and does nothing but errors.They all seem to work good and are cheap, nonworking at the same timeIt would be nice to know just how many of the complaints are simply not setup correct,battery, or possibly damaged from being hit.Right now it is kind of a tossup between the Chrony Beta Master,CED M2,or the Pro Chrono digital.
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Old August 18, 2011, 09:21 PM   #9
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Yes, except one issue is accuracy. CED's site suggests up to 8% error among commercial units (IIRC). I know I've seen my dad's Chrony read 2700 when both my Oehler and CED both put his .308 load at 2500 fps on the same day shooting over them side by side. His is an older model, though, and in lots of instances only the % difference matters. But absolute does matter when you need to figure come-ups for long range.
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Old August 18, 2011, 10:22 PM   #10
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I have had shooting Chrony [Canada] and I have had pro chrono [China], and I like pro chrono better.

The problem I have with chronographs is that I shoot them with handguns.
The solution for that, for me, is to just shoot rifles over them.

The other problem is failing to trigger. I shoot, but the reading stays the same. My Shooting Chronies only trigger half the time. My Pro Chronos trigger all the time.




On accuracy. There is an error if the bullet does not fly over the chono straight. That straight vertically and straight horizontally. The would sum in some kind of three dimensional Pythagorean theorem.
The error would be proportional to the secant of that included angle.

The error caused by the chrono would be things like the error in the distance between the the photo diodes, the error in the frequency of the quartz crystal oscillator, ect.

Those errors are pretty small, compared to the spread between shots.
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Old August 19, 2011, 08:49 AM   #11
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In the case of my dad's Chrony, a difference in the sensitivity of the diodes seems to be one of the culprits. They aren't matched pairs, as they should be, ideally, and they seem to be biased at currents low enough that capacitance alters their response speed as the light level drops. We can change the reading over 100 fps just by tilting the thing on a tripod a little one way or the other so the incident light angle changes a bit. That seems to move the sensors to different parts of their response speed curve, and the two aren't in the same spot.

The Oehler avoids that issue by having the most sensitive screens in the industry. In summer can use mine right up to dinner time with no problem. The CED M2 has the newest approach, which is sensitivity self-adjustment to the ambient light conditions. It also has an infrared LED light bar option for indoor use that can be run outdoors on batteries for critical applications. IPSC's nationals, for example, use a pair of CED's in tandem and wired that way and placed inside light blocking boxes to determine power factor of participant loads. That way nobody can complain they were cheated by changing light conditions or by false readings, since the two units have to agree closely to consider the reading good. The Oehler handles to two-chronograph double-check issue by having dual stop screens, with one in the middle that has to read withing 50 fps of the other to verify a good reading.

Except for comparing readings with other units, side by side, I don't know any way for the average person to know how accurate his readings might be, and even then it is one uncalibrated instrument tested against another. .22 match ammunition fired from a 24" barrel is supposed to be close to its stated velocity on the box. I was told Ken Oehler likes using a BB gun, but having watched my old Feinwerkbau air pistol's velocity drop and get all erratic as the springs aged, I can't say I trust the constancy of any spring-operated device over time. I've thought up a couple of calibrating schemes for these things, but haven't done anything about it. So far, Doppler radar is the only sure thing and the only home unit I've seen output from is still, uniquely, with the retired radar engineer who designed it.

To Clark's point on keeping the bullet straight, I now set my chronographs up with a laser bore sighter. I get the gun clamped in place on bags with the sights on the target. I open the action and stick an ECI flag in it that has the words "Remove Laser" written in black felt pen on it. I stick a laser bore sighter in the muzzle, turn it on, verify the sights haven't moved. I then set the screens up so the laser spot is in the center of both. I often just use the palm of my hand to spot its location, letting my fingers find the same vertical position for both screens and eyeballing the horizontal centering, but you can make a cardboard target if you are worried much about that precision. The smaller the angle, the less error results from an inch of error, so you only need to be pretty close to be within shot-to-shot velocity scatter. The further the screen spacing the better, as far as that aspect of precision goes. Having a target up keeps the gun pointed to the same place each shot.

I don't like the computer being attached to the screens. Neither the Oehler nor the CED display will be shot if I hit a screen because they are out on the ends of wires.
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Old August 19, 2011, 12:12 PM   #12
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So are Pacts unreliable and not a good choice? I do like their separate computers and screens, since they all say shooting one is a matter of when.

I'm still resisting the peer pressure to buy a chronograph. Two reasons.....one is the same question the O.P. has. The other is I'm not into competition, especially the Long Range variety, so why do I need one? Got by for 40 years, so far....seems like an unnecessary complication unless documenting velocities is part of the hobby fun for you.

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Old August 19, 2011, 12:30 PM   #13
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The pacts seemed to be in the same hit or miss boat as all the others and seems to have bad customer service.Factor in that they are more expensive and I'm not really concidering one.
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Old August 19, 2011, 12:41 PM   #14
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See that's just it. Pay out the nose for an expensive one or pay little and get hit or miss. I don't think the Pacts are that far out of the range of the Chronys and Pro Chronos price-wise, when you consider those last two have computers out there to get shot.

But they do all three seem to be in the same hit or miss arena.

On customer service? I don't know. I do know that customer attitudes affect customer service the most. A good reasonable customer who doesn't scream and yell over the phone, nearly always gets better service than the other kind.

The other kind are the most vocal on forums as well.

One more thing.....the only ones I for sure am NOT interested in are the ones that put their computers out there to shoot. I know me.
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Old August 19, 2011, 01:30 PM   #15
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The chronograph has a couple of other uses. Absolute accuracy doesn't matter as much if you don't shoot at ranges over 300 yards, but repeatability does. If you have a repeatable chronograph there are a couple of things it can do for you even for closer ranges. For one, suppose you have a pet load, but buy a new lot of powder or primers that might not be exactly the same. You go to the range with the new components and the last of the old ones. Shoot the old ones, then adjust the powder charge with the new ones until you get a match. The barrel time should be quite close at that point and remain on any sweet spot you found, and you've got your new load in fewer rounds than it takes to completely retest for best group. Note that this only works with the same powder number and not for a different number owing to difference in burning characteristics.

Another use is as an additional subjective pressure sign when working up new loads. See item 16 on this list. I figure, the more pressure signs you have to work with, the easier it is to stay safe.
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Old August 19, 2011, 02:54 PM   #16
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There's no reason to ever shoot the sensors. Place a 4" high piece of cardboard immediately above the sensor base and set the screens up. If you can see the target fine, if not lower the screens.
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Old August 19, 2011, 06:59 PM   #17
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dunerjeff, the Oehler 35p came out 1987 and I forget what I paid for it but at the time it was expensive compare to some others. .

I guess mine is almost 25yrs old if I take the cost and spread that out over the 25yrs I've used it been pretty cheap cost per year.

It's just one of the tools we have.
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Old August 19, 2011, 07:45 PM   #18
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My old Oehler 33 just keeps on tickin' - and I still have to original "spare" screen. Get one with the guts on the bench.
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Old August 22, 2011, 12:24 PM   #19
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Quote:
The chronograph has a couple of other uses. Absolute accuracy doesn't matter as much if you don't shoot at ranges over 300 yards, but repeatability does. If you have a repeatable chronograph there are a couple of things it can do for you even for closer ranges. For one, suppose you have a pet load, but buy a new lot of powder or primers that might not be exactly the same. You go to the range with the new components and the last of the old ones. Shoot the old ones, then adjust the powder charge with the new ones until you get a match. The barrel time should be quite close at that point and remain on any sweet spot you found, and you've got your new load in fewer rounds than it takes to completely retest for best group. Note that this only works with the same powder number and not for a different number owing to difference in burning characteristics.

Another use is as an additional subjective pressure sign when working up new loads. See item 16 on this list. I figure, the more pressure signs you have to work with, the easier it is to stay safe.
Unclenick....You made some good points....especially the double check on pressure. A few months ago as I was testing a few .308 loads (LC Military brass) in a DPMS, I noticed that TWO of the rounds flattened the CCI primers. (out of 50) A chronograph would have given me comparative velocity data that would have easily confirmed suspicions of a significant powder measure fluctuation in those two rounds. (or worse)

I may be looking for a chonograph after all. For me at least...a separate computer is still not an option. The CED may be the best compromise from what I'm reading. My wife will be thrilled...she has a hell of a time coming up with ideas for Christmas gifts for me. That's just the way it is when you get old and have already accumulated what you need.

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Old August 23, 2011, 09:20 AM   #20
dunerjeff
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That double checking and adjusting new powder to match the old powders is one of the main reasons I want a chrono.That and I want to do a bit of testing on the small primers vs large vs mag in 45ACP,not to mention wanting to know how much variations some of my loads are getting. The Oehler is climbing it's way to the top of my list,they have a good name behind them with the 33 though I don't know if the 35 is available other than a "kit" for around $500.00 (yikes)then I'd have to say no.
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Old August 23, 2011, 09:21 AM   #21
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A chronograph is one of those tools you may not justify easily at first, but will quickly become addicted to using. You'll find your cross-checking extends to seeing what loading technique produces the least velocity spread. You'll be checking different primers, temperatures, brass brands, etc. It'll probably raise as many or more questions for you as it answers, but that's part of the fun.
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