I've had an F1 for awhile, til a few years ago, it died by a gunshot wound.
It worked fine, easy set up, and the little box on the bench was easy to read.
Besides a magno, anything new ?
I am being offered a Caldwell, but reviews aren't favorable.
Can anyone fill me in on this particular model ?
I would like something like I was used to.

Plain and simple basic would be a pro chrono by competition electronics. On my second. First one died by 45 Colt. You can spend more from there.

I think I asked $15 for my Caldwell and the buyer ended up paying less and I had to deliver it.

Oh !
That's not a good review !
Why'd you sell it ?
Tell me about your time with it.

I have a old chrony. After the Labradar showed up I only use the chrony to validate my arrow speeds at the target.

Labradar IS the reference. Get a trigger and $15 battery pack and never look back.

**the only fly on it is 4k fps .22 and smaller projectiles.

Sometimes it worked is all I'll say.

Ok. Thanks.

I have a cheap Caldwell. It works, but on a clear sunny day it needs to be in shade. It gives all kind of wonky readings if it has bright direct sunlight over it.

It also needs to be quite a distance back from a muzzleloader or the smoke makes it read goofy, too.

I had a pact. After 20 years it finally took a dump. Hasbeen

I run my optical chronograph upside down in the sun and it solved all the headaches. I don't ever use sky screens now.

Some of you need to upgrade.

The old steam driven and pneumatic chronos were notoriously inaccurate. At the very least, get a gas driven one like the Stutz Packard 1000. They’re the bees knees!

Interesting thread here; as I have been wondering about chronographs lately. My shooting chrony dates back to 1997; had it upgraded in 2007 for more features & memory and been using it ever since. About a week ago I was using it and started thinking about how old it is and surprising it still works. One of these days I'll probably be looking for another and last I knew Shooting Chrony is out of business. So I'm also wondering what's good without spending mega-bucks? Probably don't use a chrono more than 3 or 4 times a year.

Papat mentioned this one. The Pro Chrono by Competition Electronics. It is almost as good as an Oehler, but has fewer features.

If you want to start an Internets war, just say that the Pro Chrono is all you need. Oehlers are great, but an unnecessary expense for almost every shooter.

Another vote for this unit. I havent killed mine yet but did blow the OEM Bluetooth sending unit right off the port side! On Bluetooth #2 now.

I'll tell you a 60 grain Ballistic tip will do a number @ 15' out of a 5.56mm

Bought a shooting chrony beta.

Hope you did not pay very much, it is a POS like the F1 you shot !!!!!!!!!!!

Disagree, worth every penny in my book. on the other hand every penny spent on a shooters chrony is money wasted

I just want a machine to give me velocities whenever I decide to use it. It isn't going to be used every time I go to the range, and cheap is good for when a bullet hits it !!
Thank you for your suggestion of a proper chronograph, and your opinion on what I purchased.
I hope you slept well, knowing you informed myself, and many others of your knowledge about these things.

splattermatic,

Do want just want velocities, or accurate velocities? Over the three decades since Shooting Chronys appeared, I've seen them provide more inaccurate velocities than any other chronograph.

My Oehler 35P does require a bit of set up, but I can trust it.

Well damn MD, before affordable personal chronographs were available I used to go out zero at 100 then see what the drops were at 200 and 300 then looked in a ballistics book for velocity closest to the drop at each distance, accurate? Hell no, but it was close enough to kill critters with.
As an aside to this for many many years the shooting crony that I still use at times gave more accurate velocities than my previous method so it served the purpose. Now isn’t that the real point?

I'm glad that you got what you wanted. Happy days!

I'm not into serious, I have to know the exact, to the single digit velocity.
How does one do a ladder test ?
I'm sure a chronograph is not 100% necessary, but it's nice to see a node.
If it works great, if it doesn't always ,,,,, we'll I guess I'll just @ it....

As usual, the first response is usually the best.

Totally agree. I got my first ProChrono in 1989 or 1990 IIRC. Finally replaced it four years ago. The replacement cost the same as the original.

Any votes for the magnetospeed?

The Magnetospeeds work very well, but cost more than either a Shooting Chrony or ProChrono.

They also usually require more shooting (meaning $$$ for ammo) because used in the designed way, by attaching to the muzzle, they affect both accuracy and point-of-impact--unless you buy or make a separate stand for them.

All of this chronograph discussion has been hashed over before on this forum, but seems to come up again every couple months.

I took my Labradar to the range yesterday and shot 20-plus strings of .45 ACP through it …. nooooo ….. with it.

Mostly 8-round mags with a specific powder charge each working up loads.

It was very nice not to have to shoot 200 rounds offhand through a “window.” It allowed me to put up a bunch of bulls on one target and have a new aiming point for each mag.

I like the data output per mag. Provides a ton of “fireside reading” for later.

The Labradar ain’t perfect, but there is a lot to like about it.

Wants, in order of priority for ME:

1.
Let me return to a previous string and add to it, so when I am shooting rifles I can be shooting one while another (or more) are cooling, and I can go back and resume collecting data on a now-cooled rifle.

2. Capture shotgun data.

3. Capture ultra fast small caliber rifle data (it captures my .223 loads just fine).

4. Capture arrow speed.

I am sure there are others …

I like them, but for me, the biggest advantage with the MS is shooting on a public range. You don’t have to inconvenience other shooters to get set up. Or tear down either. I use packing tape wrapped around the MS and the barrel to prevent it from moving.

To expedite set up with the Pro Chrono, I get the rifle aligned to the target and use a length of Jute attached to the front rest. I extend the Jute parallel to the barrel, and set up the PC. It cuts down on the back and forth you see others doing with their set up.

Since apparently many have missed the many threads about chronographs on this forum, which have included my mini-essays on using a bunch, here they are again:

Have owned at least one chronograph since 1979. My first was in the early days of light-screens, so included both light-screens and "break screens," made of metal foil. They recorded the same velocities, with a 2-foot spacing, with a specific .22 Long Rifle factory load, and I used that chronograph (which is no longer made) for a dozen years. The velocities it provided also matched "reality" during numerous trajectory tests at 300+ yards.

I bought it due to just getting into gun writing, after years of writing about hunting, fishing, Western U.S. history, wildlife biology, and other stuff. Even back then it was obvious a chronograph was going to be necessary for any serious gun-writing.

That chronograph finally died in the early 1990s, and the company was out of business. But I still had the owner's contact info, and called him. He said he could repair it, but in the meantime more affordable chronographs had appeared. One was the Shooting Chrony, and believe it or not L.L. Bean sold them for $50. I bought one, checked it against the same .22 LR load, and found the velocities matched.

That was the first of three Shooting Chronys I owned, and all of them eventually proved unreliable, either due to aging or light conditions. I never could quite get them past varying light conditions, no matter what trick I tried. During that period (which lasted around a dozen years) I not only had my 3 Chronys result in some very strange readings, but also saw others at the local public range go bat-schidt.

About that time Ken Oehler started making the 35P again, so I got one. Didn't find it nearly as hard to set up as some people do, partly due to his excellent instructions which came with the chronograph.

After that I used the 35P as a test for newer chronographs, setting them up together to see what happened. Have since tested three ProChronos against it, the first one during a long afternoon where the sun went from high overhead to close to the horizon, with rifles in calibers from .17 to .30. It provided an average velocity very close to the 35P. Have since owned two more ProChronos, and they also tested very well. (The reason I don't own 3 now is I gave two away to young, semi-broke rifle loonies, including one who has three kids. Also gave one of his kids her first deer rifle.)

As somebody mentioned earlier, ProChronos don't provide the detailed info of the Oehler, but for the average handloader they provide a valid average velocity. One of my younger friends, a former Montana hunting guide and U.S. Army sniper who served more than one tour in the Middle East, has been using an early ProChrono for many years, and it still works fine--and he shoots a LOT.

Magnetospeeds also work fine. I've use two quite a bit (after testing them against the Oehler), but prefer to use them on a separate mount so I can test accuracy/POI and velocity at the same time. This is because I do this for a living, and my average range session involves 3-5 rifles. For somebody who doesn't shoot as much they work fine when mounted on the barrel, as designed.

Tried a Labradar, and loved it for the half-dozen sessions. It not only provided the same velocities as the Oehler, given the difference between sitting next to the muzzle and the Oehler 10-15 feet in front, but set up quicker.

Then one day it wouldn't "read" the velocity of 6mm 135-grain Hornady A-Tips. The Labradar company states they won't read bullets below .22 caliber, or velocities over 3900 fps--but the very small base of the A-Tip wouldn't provide a reading. Luckily, I had my ProChrono along, which worked fine. (I was also up against a deadline for a magazine article, and the "cheap" ProChrono saved considerable time.) If you don't shoot smaller bullets, or bullets at velocities over 3900 fps, The Labradar works great. But if and until the Labradar folks solve those diameter/velocity problems, it doesn't work for my purposes.

Will also comment that no, we don't "need" a chronograph to handload. But since buying my first one have learned that they save a lot of time and ammo, partly by reducing the "need" to add more powder until "pressure signs" appear, and partly by providing accurate velocity info that helps considerably in predicting downrange trajectory.

Which is why the Pro Chrono is the best bang for your buck, if you will pardon the pun. It was made better with the introduction of the DLX with Bluetooth built into it. I use my phone or a tablet and have the older version with the Bluetooth module strapped to the side. Before I retired, I got the Pro Chrono and compared it to the Oehler we had at the school. There wasn't enough difference to justify taking the Oehler to the range every time, so I packed my Pro Chrono instead.



That was me. Most people want individual shot velocities and averages in a string. When shooters are testing five or ten reloaded cartridges, almost everyone wants the avg of strings with different powders (and targets with holes grouped tightly together).

It is your choice to use the Magnetospeed mounted separately from the rifle. I suspect their R&D folks liked the idea of a muzzle mounted system however, so that shooters didn't have to interrupt the line if they had to access the chronograph. Set up is faster too. That makes perfect sense.



I believe this is the most useful part of having a chronograph. If you are matching the published load velocities for a specific bullet weight and cartridge, it's reasonable to assume that all is well. Higher than expected velocities, paired with increased felt recoil and funny looking primers are a great reason to double check your loads. Better safe than sorry.

I’ve got a LabRadar and I’ve had it read 17 caliber bullets from my Hornet with zero issues. Haven’t tried anything over 3900 fps. Don’t usually shoot super fast cartridges. I have found the LabRadar is extremely particular about where it’s aimed. That’s the only time I’ve had issues with it picking up shots. Once I had it aligned at the target well it’s picked up 17 and 20 cal bullets with zero issues.

My Labradar was aimed well enough to pick up other bullets with no issues when it refused to read the 6mm Hornadys A-Tips.

Their flat base (which is what the Labradar reads on any bullet) is about .15 inch in diameter. Never had it read .17s, and don't know of any boat-tailed .17 caliber bullets--or at least none I tested were BTs. Also had it fail to read anything close to 3900 fps. Neither my ProChronos or Oehler have failed to read any bullet. Which is why I sold my Labradar.

If yours works for your purposes, great! I would definitely buy another IF those problems are solved,

Steve,

Thanks for your comments.

I am also sure the MS folks liked the simple muzzle-mounting as a selling point--especially since it can be done on any range, without having to spend time out in front of the bench.

That said, with the separate mounting of the Magnetospeed I use, it's really easy to use it for several rifles WITHOUT switching the chronograph to various rifles. Instead I just set it up, and make sure the muzzle is close above the V at the rear of the MS with each rifle. This is far quicker when testing several rifles. The only potential problem is whether the bench is long enough to accommodate the stand. So far it's worked fine on both the concrete tables at the local range where I'm a life member, and on the Stukey's portable bench I often use on public land when the other range is too crowded for my purposes.

John

JB, how close does the sensor need to be below the bore? No more than an inch? Two inches?

When hearing talk about chronograph numbers that are better than the mfgs stated margin of error, I just smile and nod.

Good shootin' -Al

Uncle Alps,

Half an inch below the barrel itself, if I recall correctly.

Had a Shooting Chrony, purchased in the '99 time frame as I recall. It's still ticking but in other hands. Light was a problem, solved by removing the sun shades on bright days with Ol' Sol overhead.

About 2-3 years ago I purchased a Pro Chrono with a little box that gives a readout by the shooter. Both have been cross checked, same day, same loads, results varied about 3-5 fps as I recall. I like the Pro Chrono. I have tried for over 20 years to shoot one of the dang things but have failed miserably. Tips appreciated.

DD

While you may have precision, your accuracy ain't worth a hoot.

1. YES. I contacted the manufacturer a couple of years ago requesting this function.

3. Agreed. Though I’ve been able to capture .17 HMR data, but as mentioned, aligning of the LR with the axis of the bullet’s trajectory becomes critical with small bullets.

4. I’ve chronoed arrow speed several times, but using Doppler triggering mode is necessary.

Lots of people poo poo Shooting Chronys, but they were one of the first affordable chronographs and a step along the way. Certainly, technology has improved, and the fact that they are no longer in business might indicate that they didn't keep up with the times. You'll look back at your Chrony with fondness remembering the day you finally put a bullet in it.



If you wish to shoot it, use a fluorescent green sticker and place it in the centre of the face of the Chrony. That's your aiming point. Ta da!

I use the remote trigger on my bows and it works well. I set the radar on a tripod and shoot beside it. The triggered radar and my pro chrony are typically parallel in readings.

The alignment with small pills and the correct offset are critical for them to aquire the shot.

Per the instructions, which come with the unit and are available on the manufacturer's website, the distance should be 1/8" to 1/4".

Thanks for jogging my memory....

Since "building" my stand, have just tried to get the muzzle as close as possible to the V without touching it. This has worked very well.

That's good to know. I just bought a used Magnetospeed V3 and haven't been able to get out to use it yet. I was wondering how crucial it was to be exactly a quarter inch below the bullet. I'm making a stand like you and others have done so I can test groups at the same time.

I'm on my third chronograph. I bought a Chrony while still in college in about 1990. It worked okay for several years. Then I tried an RCBS, which sometimes was unreliable. Now I use a Competition Electronics I bought from Midway USA for not much more than I originally paid for the Chrony, and it serves my modest needs. It's nice knowing a ballpark figure for my velocities, ranging from 700 fps for target loads in my .45 ACP to nearly 4,000 fps in my .220 Swift, and many points in between. I don't use it a ton, but I also can't imagine living without one, either. Kind of like my 5" .357 Magnum S&W 27-2.

Got the Shooting Chrony, and shot over it this morning.
Fars I can tell, it works just fine.

I don't shoot as much as I used to, but used to shoot quite a bit and had the ProChrono Digital since (IIRC) the late 90s. It still works, sold it and got the DLX so I could record the info on my phone. Great reliable Chrony that doesn't break the bank.

I have excellent results with these two chronographs

https://oehler-research.com/product/35p-complete-kit/

https://www.doublealpha.biz/us/ced-m2-chronograph

They agree with each other so accuracy is never doubted

I have a ProChrono DLX that is Bluetooth connected to my phone. Keeps the shot strings in a file on my phone app. Works great for what I need it to do.

Ron

^^^ THIS

I have been using my little Chrony since about 1990 same one, 10's of thousands of rounds over it and it is still working very well, in fact was using it yesterday, like the bunny takes a licking and keeps on ticking

Had a Shooting Chrony F1 for years, it worked but not great. The lighting had to be just right as well as the sun screens and even then I would question the readings. Then I got a good deal on a ProChrono DLX, Much better in every way and just a little more money. I'm convinced it is about as good as it gets for the money.

I am going to try that! Does ground cover seem to matter? GD

Anyone using a Pact? I have been gifted a brand new in the box one but haven't used it yet?

In 5 minutes I shot handgun holes through (2) shooting chronys and (1) pro chrono.

In that last 5 minutes I could see I liked how the pro chrono triggered.

Then I bought another pro chrono and only shot rifles over it.

Years went by with no holes in the 4th chrono.

Then I shot a group with a handgun and then set up chrono #4.

Now 10 years later, I have still not shot any chronographs, but target practicing with each handgun before using the chrono.

Other chronos still in box, will probably stay there until I die of old age. I have overcome my pi$$ poor pistol shooting.

This is my experience as well. My basic Caldwell was my first optical chronograph. I have no idea if every brand and model of optical chronograph is as finicky, but my Caldwell sure is.

If sky conditions are right and the range is empty, I can get it work pretty easily and produce repeatable measurements.
Those are two pretty big "ifs" at times. Maybe there are some handloaders with enough experience they can set up a chrono and get to shooting. I find I need several trips back and forth to the bench to check alignment. It probably doesn't help the ground on my outdoor range is not flat or very level.

As I said, I hope it is my last optical. A new LabRadar just arrived. I hope this LabRadar let's me capture reliable data regardless of the sky and without having to spend time downrange fiddling with a setup. I think it will. Even if the LabRadar is everything it's cracked up to be, I'll still hang on to my Caldwell.

Gentlemen,

Would someone please explain the "song and dance" that's involved in setting up an Oehler 35P.
Isn't there setup time with all models? Are they considerably less time consuming?
I think a lot of shooters would like to hear it firsthand from the fellows using them.
Thank you in advance for your time and help.
Soup

I always wonder how shooters with inexpensive chronographs know they're accurate.

For my job, they have to be, which is why I've owned an Oehler 35P for many years. All the other chronographs I use are tested directly against the Oehler. The three Shooting Chronys I've owned have not worked out in the long run--though in one instance the problem was a .41 Magnum bullet through the center of the display. But the other two eventually ended up being erratic.

I just look at published reload data with velocities listed. That gives me a ballpark number. If my cheap, set up gives velocities close to those publish figures, I call it close enough.
If my numbers are off, then I know not to believe it.
Simple....

Have seen plenty of rifles that vary 200+fps from published data, in rifle cartridges that get around 3000 fps even when using exactly the same components in the same barrel length. Have seen even more variation when changing bullets of the same weight, especially today when bullet construction can be far different than it was back when almost every bullet was a simple cup-and-core.

Then there's the effect of changing seating depth, different manufacturing batches of powder, etc.

I prefer knowing the muzzle velocity, not coming within 10% or so.

The two main benefits of the Oehler are the ability to control accuracy and verification of every shot.

Controlling accuracy - Longer screen spacings are more accurate. Velocity is measuring time to travel a distance. If that distance is small, errors are magnified. In other words, if your measurement of the distance is off 1/8" it is more problematic on a 12" spacing than it is on a 120" spacing. Also, "Seeing" a bullet is difficult. Does the sensor see the nose, midpoint or tail? Does each sensor see the same part? If you have a short spacing and the first screen triggers on the tip of a long bullet but the last screen triggers on the base you will get an inaccurate reading.

Verification of every shot - The Oehler actually makes two measurements of every shot. They are expected to be very close. If they are not close, you know you have a problem. It is like running two chronographs.

The "Song and Dance" involved is that you have to position the screens in front of the gun and then shoot thru them. It is not difficult. It is even easier if you set the firearm on sandbags, pointed at the target, and use a laser boresighter to project a beam forward. You can then align the screens quite easily.

Longer screen spacings make it a bit more difficult but still doable. If you go over about 8', you probably need support for the middle screen as well as the two end screens.

I usually test with a 9' spacing.

I've said it before: We hear a lot of people say they verify their chronograph by comparing it to an Oehler. I've never heard anyone say they verified their Oehler by comparing it to another brand of chronograph.

All chronographs can give good data. All can give bad data. I'm not fond of a LabRadar but I am very fond of 2 LabRadars, run at the same time. I've documented velocity variance of about 60 fps, due to setup error that I would not have noticed without the 2nd unit. It IS NOT a fault of the machine. Once noticed and re-aligned, the problem was fixed.

I'm still using an Oehler 33 that I bought in 1985. It started to give erroneous readings about 15 yrs ago. Oehler had me send it back and in 1 week I had a new one. I'll probably use it until they stop making D cell batteries[it takes 6].

I had a Pact chronograph for 25 plus years. The only problem was using it on a cloudy day. I gave it to a young guy just starting to reload. I bought a LabRadar almost two years ago and have not been disappointed.

When affordable chronographs hit the market, a few people bought them and were horrified to learn that their favourite factory ammunition or handload didn't launch as fast as advertised. Yikes! Was the chronograph wrong? The reloading manual? The ammunition manufacturer? My technique?

Perhaps you had a favourite recipe, taken from your favourite manual, and when you ran it over the chronograph, there was a big discrepancy! Did you change your load or stop using it altogether? It was probably a load that worked well on game, but you were disappointed that the advertised 2600 fps MV was actually 2400 fps MV!

Some of that might not have been your chronograph's fault. You have to read the instructions that come with the recipe or on the ammunition box. Often, the barrel length and throat condition of your rifle don't match with the test equipment. I used to find this with a lot of used and surplus rifles.

Your 22 inch barrel compared to their 24 or 26 inch test rifle/universal barrel? Or a well used rifle with a cavernous chamber or a different sized bore?

Sometimes, the chronograph isn't the only variable.

Back in the dim times, before affordable chronographs, ignorance truly was bliss!

With all the available chronographs, many very affordable, it would be an interesting article comparing them to something known for accuracy such as the Oehler. I remember you mentioning at one time the ProChrono was also fairly accurate compared to the Oehler and after having the Digital for 20+ years it reinforced my confidence in it and I upgraded to the DLX.

Bingo, John!

Good shootin' -Al

Just how damn accurate do they have to be for the average shooter where the longest shot taken at a critter or piece of paper is 300 yards? 1% or 2% or what. My 35P was a want, not a need as my chrony was more accurate for my needs than my previous method.

I doubt that it matters. -Al

I would argue that, for the “average shooter”, they aren’t necessary at all. For most, as you said, they are a want, not a need.

Maybe it’s “keeping up with the Joneses”.

I would have to agree Steve which is why I am amazed that when a dissing point on one is how inaccurate they are. I know the OP bought a Chrony due to price and it fit his criteria. I can understand JB’s position but also understand that an exact velocity to the Nth degree isn’t going to kill a critter any better, it isn’t going to help me win a 1-2-300 yard group or score match it just makes you feel better and maybe, just maybe it will put me one step ahead of the Joneses.

Might be interesting to go old school throwback method. Useful for extended range testing for energy/velocity?

Ballistic Pendulum

Good one.

On a serious note I read a story where Billy Dixon had somehow chronoed his supposedly borrowed 50.90 Sharps loads before before making his 1500 yard shot. It was said he stated “ I knew exactly how fast that bullet going.”

Sarcasm off.

Amazing how a malcontent can twist things around using part of the truth but far from all the truth

I'm happy with the Chrony.
As was said, I'm good with what I paid, and it's to see if my loads are near where the book says they should be, with all factors involved.
Shot the same loads over it twice now, and same velocities.
Are they accurate ?
Using JBM, and the mil marks in my 10x mil quad super chicken, I smacked a soccer ball sized rock at 580 yards !
Is my old Leica lrf 1200 accurate ?
Another questionable factor involved....

My first "chronograph" was a ballistic pendulum, put together with the directions in P.O. Ackley's first volume of his HANDBOOK FOR SHOOTERS AND RELOADERS. Built it in the basement of the first house I bought, which was outside the "city limits" of the little Montana town I lived in then. That was about the time electronic hand-calculators started replacing slide-rules, and I had one. As far as I could tell, the pendulum worked.

But must also admit that I am not obsessed by muzzle velocity, after going many years without a "real" chronograph, instead actually shooting at various ranges with my rifles to determine the trajectory. But when I started writing about hunting rifles (among the many other subjects I wrote about back then, from Western history to fishing) and realized that an actual electronic chronograph was required to be published--rather than listing "approximate" velocities from loading manuals, which used to be common.

Bought my first electronic chronograph in 1979, when still in college, a unit that hasn't been made in years. It included both "break screens"--made of a grid of thin aluminum glued to equally thin paper--and light-screens. Tested them against each other, and came up with the same numbers. (Oh, and it was one of those chronographs where you turned a dial that pointed toward numbers from 0-9, and wrote down which little red lights beside each number lit up. Then you looked through a booklet that listed the velocity of that series of numbers.) The major test I made was running some Remington .22 Long Rifle ammo through my old Marlin 81 and finding the velocity closely matched the chrono.

That chronograph eventually died in the early 1990s, and since by then more of my income was due to gun writing, I bought one of the early Shooting Chronys, which believe it or not cost $50 from the L.L. Bean catalog. Tried it with the same batch of Remington .22 LR ammo, and the results were very close.

After that went through a bunch of chronographs, including two more Shooting Chronys. Learned the various ways they can go wonky--or work well. Along the way got to visit several professional pressure labs, and learned a LOT--including the fact that EVERY one used an Oehler chronograph of some sort. (As Buford Boone noted, have never heard of anybody testing chronographs for accuracy against anything but an Oehler.)

But again must emphasize that I do NOT believe every handloading hunter needs an accurate chronograph. Though along the way I also learned that muzzle velocity has a far closer correlation to pressure than any of the traditional "pressure signs"--and having accurate velocities can also save plenty of time when testing loads for POI at longer ranges--and am not talking 500+ yards, but even 200-400, depending on the cartridge. All of this eventually saved me a lot of time--and components. (Dunno anybody who doesn't want to save on components these days.)

Might also mention one of the more extreme instances where "published data" did not come anywhere close to reality. A good friend in the gun-writing business bought a 7mm Remington Magnum back when it was still one the hottest-selling rounds. He loaded up some 160-grain bullets and found they shot well with the load listed in the same bullet manufacturer's manual, which supposedly got 3000 fps. He used it for years in western Montana to take big game from deer to black bears and elk, and boy, did it knock the snot out 'em! Man, that magnum sure did a job.

Then he got into gun writing, a few years after I did, and had to buy a chronograph. I can't remember which brand, but it might have been an Oehler, since Shooting Chronys didn't exist then. He found out his devastating "magnum" load got around 2700 fps, about like "modern pressure" loads in a 7x57. But he never shot anything beyond about 250 yards in that steep, timbered country, so even the extremely "slow" bullet still worked great. But he would have been surprised at the trajectory if he shot anything beyond 250 yards.

No, handloaders don't need chronographs--and in fact I have long felt they hamper some handloaders, who're always trying for absolute maximum velocity. But "affordable" models have been around for at least 30 years now, and buying and using one doesn't make any sense unless it's accurate.

It's all about your satisfaction. If, in the future, you wish to get deeper into it, you have that option.

Not too many years ago, we grabbed a box of ammunition off the shelf, or put some handloads together that were reasonably accurate. We trusted the manufacturer or the company that produced the manual. We trusted what was written about our loads. Oddly, everything worked.

Enjoy!

Edited because that Quote, above, didn't format right.
Bryan Litz did just that. It is an excellent chapter in one of his books. I actually think he did the best job of comparing chronographs and explaining how they work that I've ever seen.

And, yes, he used an Oehler as the "Truth" to which all others were compared.

Yep, and it was another major confirmation of my decision to get an Oehler 35P more than a few years ago.

One of the reasons I recommend the ProChrono to handloaders who don't want to spend much on a chronograph was my first afternoon of shooting several rifles for about four hours over both chronographs, with the ProChrono Pal placed a few inches in front of the Oehler. Shot from mid-afternoon until the sun was angling down, and got essentially the same results, with cartridges from the .17 Fireball up, and got basically the same results--though due to the longer distance between the Oehler's screens it's far more meaningful when analyzing stuff like standard deviation. (Am also still amazed by handloaders's who believe the SD from 3-shot strings is meaningful, whether from a small chronograph or an Oehler.)

Have since purchased another ProChrono and it did just as well. But that's sort of aside from the main point, that unless somebody knows their inexpensive chronograph is accurate, there's no reason to use one.

John, I tested my Pro Chrono against a pals 35P and there wasn't more than single digit differences between the two. One of the things that makes a difference on mine is using an cheap furnace filter instead of the provided sky screens.

Good enough for the girls I go with! 😉 -Al

Which, as I posted earlier, is what I did as an armourer. The important thing to add is getting your unit calibrated periodically. What is Oehler's frequency recommendation? ex. a time frequency like once every six months, or hrs of operation before calibration. This would be something those who use a Pro Chrono should follow too. They state that accuracy is +/-.5% of measured velocity or better. For example, a 3000 fps load would be no more than 15 fps out. Say, 2993 to 3008 fps.

This is no different than getting a torque wrench or other precision device calibrated. For example, our torque wrenches were calibrated every six months.

Calibration ensures that what you are using remains accurate. Or, for the Campfire, and to be blunt, demonstrates how anal you are about accuracy.

Calibration of a chronograph is interesting....

At one time, NISt had a container of speed standards, but when they opened it, and the standards sped off into the bush, and have not been seen since. That's a joke, of course. But it is true that there is no such thing as an NIST speed standard.

Speed is a derived quantity, derived from distance and time. We do have NIST traceable standards for those quantities.

Distance between the photosensors is fixed.

Crystal controlled oscillators are used to measure time. Even a cheap crystal is very stable. The crystal will age a bit when first put into service, but will not change enough to matter. If you want to check the oscillator frequency, you can make a little pickup loop, place the loop near the circuitry, and feed the signal to a frequency counter. But that won't be very revealing, since the crystal is very time stable, and you'll always get an answer close enough to nominal that the difference won't matter.

Once the chronograph is calibrated at the factory, it pretty well stays calibrated.

Now the LabRadar works very differently. The outgoing signal is mixed with the return signal to create a "beat frequency", and it is trivial to measure that to four or five significant digits. Ken Oehler has said that getting the effective spacing between photosensors to better than 1/8" was difficult. The LabRadar overcomes that problem.

That is interesting. What, in your opinion, would be an indicator that a chronograph is damaged or otherwise out of spec? Could a component other than the photosensor or oscillator be damaged and cause the unit to display an erroneous reading?

For the most part, the circuitry either works or it doesn't. If it's not working, you don't get a reading.

For conventional chronographs, there is one condition that will definitely cause an error, and that is lighting. If you are using your diffuser screens and a cloud comes by, your readings will shift. IIRC, it's about 25 FPS with a rifle cartridge.

To do good chronographing, you have to control the lighting, and you have to stick a thermocouple to the barrel just forward of the receiver, and control barrel temperature. If you let the ammunition sit in the chamber for about a minute, the ammunition will effectively come to barrel temperature, so you've controlled both ammunition and chamber.

Those are conditions external to the chronograph.

For the morbidly curious:

The passage of the bullet makes a little dip in the light that the photocell receives. This signal then passes to a Schmidtt trigger, that provides a clean starting edge for the counter. When the counter gets that clean starting edge, it starts counting cycles of the crystal oscillator. When the second sensor gets its edge, the counting stops. The Shooting Chrony oscillator runs at 12 MHz, so if the counter gets 4,000 counts, 1/3 millisecond has elapsed from start to stop. The sensors are 1 foot apart, so the speed is 1 foot / .33333 milliseconds, or 3,000 feet per second, if I've done my math right.

The system is pretty bullet proof. Alas, the chronograph, not so much.

I've compared several Pro Chrono chronographs against other, far more expensive units. They've all been spot on. I think it's foolishness in the day and age of $99 chronographs not to use one. It's the biggest indicator of safe handloads when comparing against pressure tested data.

Thanks, Denton.

Brad, I agree for the most part.

Perhaps chronographs, regardless of manufacturer, should be used by more people to confirm safe pressures and not just velocities. It's probable that this group shoots more than the average Joe. I would not say that absolutely everyone has a need. If you need 10 cartridges to take to deer camp, following a manual should be fine. I know in the past there were a few times when inaccurate data made its way into print, but these days, it's unlikely.

denton,

I have owned two Shooting Chronys which declined in accuracy over time--and also have a local friend who had the same thing happen. They did not just quit working. Instead two started showing velocities that were obviously much higher than they should have, and changing batteries didn't help. The third started showing variation between sunny and cloudy readings of 100-150 fps. Sent that one back to get fixed, and it worked OK for a while, but I was starting to mistrust them.

Back then I was doing a LOT of shooting with a wide variety of cartridges, and eventually concluded the muzzle blast of some of the bigger rounds was shaking something loose. That's when I acquired my first ProChrono, and those problems ceased. (Purchased another PC maybe two years later, in large part to see if it worked as well, and also tested it against my Oehler 35P while shooting a wide variety of cartridges from .17 to .416 caliber. The second one worked just as well, despite me using the plain old overhead filters, instead of the furnace filters that Al Nyhus has used to good effect.

But the first also just kept trucking, so I gave the second one to a young friend with a growing family. This was several years ago, and he's still using it, with cartridges as large as the 33 Nosler--with the chronograph less than five feet from the muzzle.

John

Interesting and useful information.

Yes, muzzle blast can have an effect on readings. Besides the optical possibilities, disc ceramic capacitors (among other components) tend to be microphonic. You can strap one across the input of a high gain audio amplifier, tap on it, and hear the tapping at the output. So muzzle blast can possibly mimic/interfere with the effect of the passing bullet.

I used a Shooting Chrony for years, and did a formal analysis of the Probable Error. IIRC, the real precision (ability to get the same answer, given the same stimulus) of the system was between 1 and 2 FPS.

That said, in addition to the passing cloud issue, if you use only one section of rod to support the screen, you will get a different reading vs. if you use both sections of rod. So I had a selected set of conditions for chronographing, and carefully followed those. I got very consistent, credible results, but could only do measurements when conditions were just right. So now I have a LabRadar.

I'm a little nonplussed by your experience with declining accuracy. That should be un-possible. But anything that happens must be possible. There was a design change part way through the production run, with early units running a 4 MHz clock instead of 12 MHz. My unit was a later unit. Wonder what else they changed, and if that had any effect?

denton;
Good evening to you sir, I hope the day's been a good one for you and all who matter to you are well.

Two years ago now, the Shooting Chrony which I'd had for years began to show excessive readings at higher velocity. Strangely enough I was there with a buddy who was testing his which was a newer model of Chrony - a green one with the metal diffuser stands. He said he was getting odd readings from it on occasion as well, so we set the two up in tandem.

As a matter of practice and likely something that John has written recommending if I'm not wrong, I run a few shots with a .22 with the same box of ammo on all chrono days.

The crazy thing is that they stayed correct or at least within 20fps of where it should have been and both chronographs confirmed that.

When we chronographed a .17 Rimfire Mag my Chrony was a little bit too fast however. Then when I ran a few loads from a 6.5x55 my Chrony reading was 150fps too fast. Lastly I ran a few rounds through my .308 Norma which were loaded maybe 5 years back and in all subsequent chronographings had been consistent until that day when my Chrony readings were way too fast.

After a bit of correspondence with John and on his recommendation I picked up a Pro Chrono from a retailer here in BC who had one in stock.

All of the "known" speeds went back to "normal" again with the Pro Chrono.

Anyways that's my experience with a Chrony losing it's way, but again it was a very old one with the cardboard light diffuser holders - pre metal rods - and it'd served me for decades so I got good life out of it.

Hopefully that made sense and was useful to you or someone out there.

All the best.

Dwayne

Edit;
Both were Chrony's but different ages.

Well, anything that happens must be possible. And now we have another example of one of the older Shooting Chronys going bananas. Hmmmm......

The fundamental system is extremely basic: A start pulse, a stop pulse, a count of the clock pulses in between, and a distance divided by measured time to get speed. Such a system either works right, or not at all. The only guess I can come up with is loss of hermetic seal on the oscillator unit, or some kind of internal contamination that slowly diffuses. I've never actually seen that happen.

So I am perplexed.

I wonder if damage to a circuit board or other component would account for the declining accuracy? The reason I asked about damaged equipment earlier is because my experience has shown that unserviceabilities like cracks or impacts from rough handling do not always stop something from functioning, but will degrade performance. Muzzle blast, heat from the sun or improper handling may cause problems.

When I was in the military, I had to get regular physicals as part of my overseas duty. The medical people had a new fangled blood pressure gauge that automatically inflated and took readings. I was almost removed from duty because my pressure was recorded as being 200/95 on several tries. I asked if these BP units were properly calibrated. I was rudely told that they "self calibrate" and cannot give bad readings. Ah...

At my insistence, the doctor used an old fashioned BP gauge with a manual bulb inflator. Strangely, using the old school BP gauge, my reading was 116/74. As a technician, I know that calibration is a process of verifying and, if necessary, adjusting a piece of equipment to ensure it is operating within its design parameters. Sometimes, things can go wrong, but not disable equipment completely.

Steve, in the example of +/- .5% of 3,000 fps, the actual range of velocities displayed could be from 2985 to 3015.

Good shootin' -Al

Steve, good question. The crystal oscillator is only as good as the components that control it.



Capacitors and resistors can change values with age which will change the total output and accuracy of the circuit, and transistors due to the NPN or PNP junction also decline in response time with age. They just start getting erratic until finally giving up the ghost. So you can have all kinds of errors introduced due to voltage changes and/or bias changes to both the oscillator and the output circuitry. It’s common.


Oehler just happens to give you all of that.

Another variable that hasn’t been mentioned with the Shooting Chrony is the photodetector separation. Thus far, we’ve assumed that the separation is fixed, but inherent in the folding design is the hinges wearing over time. The sensor housings can shift slightly, as well. These factors can induce error in the readings. For a bullet travelling at a true speed of 3000 fps, and an assumed sensor separation of 1 ft, a 1/8” shift in the true sensor separation, whether due to wear and play in the hinges or to a shift of the sensor housings themselves, or both, is enough to cause an error of about 31 fps. Which amounts to about 1% of the measurement.

Ummmm.... I don't think so.

A crystal oscillators frequency is controlled by the physical dimensions of a little piece of quartz, that acts like a very high Q resonant circuit. With some effort, you can "pull" the frequency a bit, but that is on the order of 1 part per 1,000, not enough to matter in this case. If the bias isn't right, the oscillator stops. It doesn't shift frequency. Unless you are running the transistor very hot, or doing reverse breakdown, transistors go practically forever, and if they do fail or degrade, the oscillator stops. Solid state crystal oscillators either work or they don't. Most broadcast receivers use a synthesizer referenced to a crystal oscillater. You don't see those frequency drifting.

Just wild speculation: Maybe they cheaped out and used an LC oscillator rather than a crystal. The cheap way to do it is with a capacitor and a slug tuned inductor. With repeated vibration, the slug can come loose, and without the slug, the frequency of the oscillator goes up, and with it, the indicated bullet speed. If the slug works its way farther in, the opposite happens. That's a bona fide SWAG for you. If that happens to be the case, it's a poor design.

This sure turned into an interesting thread.
I'm sure learning alot about chronographs, and how they work.

Yes, it's a real issue. Ken Oehler has commented that it's hard to get the sensors aligned so that the accuracy of the effective spacing is better than 1/8". Still, a 1% error is not a show stopper, especially if it is consistent.

The LabRadar does not have that problem, and may be more precise and more accurate than older designs.

Capacitive loads affect frequency. Crystal oscillators must be matched to varying loads which account for the wide variety of crystal components available.

Maximum drive power must also be considered to prevent over-driving. If a quartz crystal is constantly exposed to overdriven conditions in excess of the anticipated maximum power, it can age quickly.

Even placement on the board can affect capacitive load, whether it's relocating the crystal itself or rerouting of other components. All of these are potential sources of mechanical resonance which have to be accounted for and tested in the oscillator circuit design process.

Alteration of the power supply load can cause a change in the effective resistance of the oscillator circuit leading to frequency drift. One solution is to use a regulated power supply, ensuring that the output voltage will always stay at the rated value of the power supply, regardless of the current that the device is consuming.

That would seem to say that any and all changes on the PC board due to degradation of other components, corrosion or heat can actually cause oscillator drift.

I always defer to the engineers for the explanation, but starting with a Shooting Chrony, and later, a Pact, a couple of Pro Chronos and a MS, all demonstrated their strengths and weaknesses.

Comparing the Pro Chrono and the MS to the Oehler showed me that these two were excellent, cheaper alternatives.

Bringing this back around to one of the original points of the thread, a Pro Chrono or MS should make most people happy.

I would like to thank men like Ken Oehler! His work was extremely important to the advancement of ballistics.

These less expensive chronographs were the result of the work he had a big hand in, and shooters have clearly benefited. You can get good results for less.

Those arguments sort of work until you start putting numbers on them. Then they don't.

A pal is working with the new AndiScan Micro doppler unit and is pretty impressed with it.

Good shootin' -Al

Both were Chrony's but different ages.[/quote]

Well, anything that happens must be possible. And now we have another example of one of the older Shooting Chronys going bananas. Hmmmm......

The fundamental system is extremely basic: A start pulse, a stop pulse, a count of the clock pulses in between, and a distance divided by measured time to get speed. Such a system either works right, or not at all. The only guess I can come up with is loss of hermetic seal on the oscillator unit, or some kind of internal contamination that slowly diffuses. I've never actually seen that happen.

So I am perplexed.[/quote]

Denton,

My first Shooting Chrony performed well, as far as I could confirm from shooting various loads (including the .22 rimfire used to test my first chronograph), and it was one of the early ones with cardboard "shades," as I mentioned previously purchased in the early 1990s.

Unfortunately it met its end around a decade later due to a misplaced .41 Magnum bullet. The two I had after that were the later models--which were the ones that declined in accuracy.

One of the things I learned from the Shooting Chrony folks during this period is that dust on the photo-sensors can cause problems, filtering in throgh the slots. Which is why I've placed transparent tape over the slots of every photo-electronic chronographs I've used since, including my Oehler. Tested that by, again, shooting the same ammo from the same rifle over the same chronograph. They all recorded the same velocities.

Well, anything that happens must be possible. And now we have another example of one of the older Shooting Chronys going bananas. Hmmmm......

The fundamental system is extremely basic: A start pulse, a stop pulse, a count of the clock pulses in between, and a distance divided by measured time to get speed. Such a system either works right, or not at all. The only guess I can come up with is loss of hermetic seal on the oscillator unit, or some kind of internal contamination that slowly diffuses. I've never actually seen that happen.

So I am perplexed.[/quote]

Denton,

My first Shooting Chrony performed well, as far as I could confirm from shooting various loads (including the .22 rimfire used to test my first chronograph), and it was one of the early ones with cardboard "shades," as I mentioned previously purchased in the early 1990s.

Unfortunately it met its end around a decade later due to a misplaced .41 Magnum bullet. The two I had after that were the later models--which were the ones that declined in accuracy.

One of the things I learned from the Shooting Chrony folks during this period is that dust on the photo-sensors can cause problems, filtering in throgh the slots. Which is why I've placed transparent tape over the slots of every photo-electronic chronographs I've used since, including my Oehler. Tested that by, again, shooting the same ammo from the same rifle over the same chronograph. They all recorded the same velocities.[/quote]

Thanks for the additional information.

Dust in the optical system sounds plausible. Another might be that the designer saved about $.40 per unit by using an inductor/capacitor oscillator rather than a crystal oscillator. You can get away with that at 4 MHz, where some models ran their clock, but not very well at 12 MHz where my particular model had its clock. But, like you, I sent my Shooting Chrony to a younger shooter and moved on to a newer design.

I suppose that I will die wondering....

John;
Good evening, I hope you all are well tonight.

Well once again I've learned something from you - thanks yet again.

What brand of transparent tape do you use? Do you replace it if it starts to yellow or age?

Without looking at it now, I'm assuming the Pro Chrono can benefit from that as well?

Our range is a dust bowl on a good day so this is likely pretty huge for chronograph accuracy and longevity.

Thanks so much again for sharing these little bits of wisdom with us, I very much appreciate it.

All the best.

Dwayne

Thanks Dwayne,

I have used the typical thin Scotch tape that comes in the palm-size plastic dispensers, but more recently have used their heavy-duty package tape, partly because it's a lot tougher and so far hasn't seemed to turn yellow. But also use it because we always have a pile on hand, since it's what Eileen uses when packaging the books we publish--and yep, I put it on ProChronos as well.

Good hunting,
john

Please don't put tape over the lenses of Oehler Skyscreen III units. While the little lens system might appear trivial, I spent almost a year on its design and did not include the effects of tape.

While I'm sure that others have encountered dusty sensors and may have solved the problems with tape, I recall only one instance where it caused a significant problem. Bruce Hodgdon reported trouble with the photoscreens in his test tunnel. When I stopped by for a visit, we removed the screen covers and found the insides coated with the firing residue from many rounds of Pyrodex and other dirty loads. A convenient air nozzle took care of the residue and operation returned to normal. Incidentally, the light slot did include a clear plastic cover; the junk found another way in.

That makes sense, Ken. I give the sensors a quick squirt of air that I keep with my camera. I presume it helps, as I have never had any problems with residue.

I confess that I did try the tape, but noticed a slight bit of crud on it. I assumed it was dust sticking to the underside.

Ken,

Have never applied tape to my 35P--but have found it helps with various "cheap" chronographs, especially in dusty Montana. As noted, got the suggestion from the Shooting Chrony folks....

Thanks,
John