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Discussion Starter · #1 ·
I am relatively new to chronographs, I have been using my shooting Chrony Master for several years now and have been happy with the results. Lately I have been working up some loads for my shorty 444 project with BTB 290 LFN GC's. I set up dual ladder tests with H322 and H4198 and headed up the ladder. At starting charges of both I was getting 2-3 out of 5 shots that would not record, and by the time I was near my max loads none were recording a velocity. The Chrony error code was bullet did not cross first sensor, which is odd because it crossed and was detected by the second sensor and everything was lined and leveled. So what is up with this? Is it the Gas checks doing something funny? The same day I chronographed 9mm, 22 lr and .223 and each shot recorded as expected. I did try moving the chrony from 12 out to 15 feet with no changes..

James
 

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I have usually attributed the failure to detect the bullet over the first sensor to muzzle blast confusing the sensor. However, at 15' it is hard to make this argument unless you have a huge muzzle blast.
 

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Discussion Starter · #3 ·
I have usually attributed the failure to detect the bullet over the first sensor to muzzle blast confusing the sensor. However, at 15' it is hard to make this argument unless you have a huge muzzle blast.
This is possible, I'm pushing the 290 pretty hard, and the start loads would catch a few of the rounds going across, that certainly diminished to none with increased velocity. Hw far out can you go with chronigraph, I ran out of monitor wire at 15'..

James
 

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Try 20 feet The gas out of your barrel is faster then the bullet and gets to the crony first and messes up your reading. It can be alignment but you say it is align and it worked for other shells so I think best bet is too close. Widow
 

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Are/were the batteries good?, every time my Chrony does that it's not enough light.
 

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I am relatively new to chronographs, I have been using my shooting Chrony Master for several years now and have been happy with the results. Lately I have been working up some loads for my shorty 444 project with BTB 290 LFN GC's. I set up dual ladder tests with H322 and H4198 and headed up the ladder. At starting charges of both I was getting 2-3 out of 5 shots that would not record, and by the time I was near my max loads none were recording a velocity. The Chrony error code was bullet did not cross first sensor, which is odd because it crossed and was detected by the second sensor and everything was lined and leveled. So what is up with this? Is it the Gas checks doing something funny? The same day I chronographed 9mm, 22 lr and .223 and each shot recorded as expected. I did try moving the chrony from 12 out to 15 feet with no changes..

James
Some time you need to remove the diffusers so the light is better to measure your speed,that is the only time my CRONY did not work because it became cloudy and the sun was playing peek a bo. :tee:
 
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Discussion Starter · #8 ·
Thanks for the hints Guys, I need to re-run my best two loads for accuracy again, I'll try moving the chrony out farther and removing the screens, the battery is new.. I also thought of building a sort of bow in front of the sensors to possibly divert the blast? Hopefully one of these gets a result...

Thanks Again!
James
 

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I'm on my 3rd chronograph in the last 20 years. I shot and killed the first one, a buddy killed the second one, and thank God the third is still going strong. Currently, I have the Pro Chronograph. Weak battery and lighting conditions are always my culprits for error and duplicate readings. I cannot escape bright sunlight at my current range and it causes a lot of inaccurate readings regardless of using the light diffusers. My previous range was semi shaded and I seldom ever had a problem with or without them.
 

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picketpin

for what it's worth, I feel your pain. I took a 5 step ladder test of .44 mags to the range yesterday to run through my R92, and had the same problem. As a matter of fact, the last time I tried testing some high velocity, heavier bullets in the carbine I experienced the dreaded "err" on the F1 Chrony. It didn't dawn on me until late last night while pondering the rather failed, dismal results of loads 4 and 5 of the five test batches that only 10 feet from the muzzle of that shoulder bruising contraption was probably bruising the screen area with muzzle blast. I also had late afternoon shade intermittently and first assumed the screens were the problem ... removed the screens and still errored. No doubt the muzzle blast was beating the bullet to the first screen .... in hindsite.

Maybe I can move the contraption out to 15 feet and not shoot it's eye out :)


JD
 
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I have had problems in the past from sunlight cast from the side of the chronograph. Solved via keeping difusers in place and puting a shade (box) beside the chrony.
 

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I got so tired or this problem, so I picked up a Magnetospeed. This chrony is strapped to the end of the barrel. I don't use it when testing for accuracy but for getting speeds while working up max loads and after settling on a few particular loads I'm interested in, it's great. I've never had a failure to read, ever. You can shoot it in the dark and it will give an accurate reading.
 

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Shoot on overcast days, without the diffusers, and you won't have any problems unless you cause them yourself. Or find a place in the shade for the chrony.
 

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Discussion Starter · #14 ·
I got back to the range this week to run some more of those shoulder pounding 444 loads and try to get them zeroed in. Any way I ran the chrono without the sky screens, moved the chrono out a few more feet, and shot when the clouds would eliminate direct sunlight on the chrono. So with the combo of all the suggestions I was able to get velocities...
Gosh you guys are smart. Thanks for all the suggestions and advice.

james
 

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Thanks for the hints Guys, I need to re-run my best two loads for accuracy again, I'll try moving the chrony out farther and removing the screens, the battery is new.. I also thought of building a sort of bow in front of the sensors to possibly divert the blast? Hopefully one of these gets a result...

Thanks Again!
James
I wouldn't necessarily trust the battery - I've got more duds with 9v batteries than any other - I think it's because they move slower than AA's and AAA's.
Then what Griz said about the diffusers.
 
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