FX CHRONO

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2D1C

2D1C

Member
Dec 27, 2016
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CA, United States
I got this thing Thursday morning and by mid afternoon I had called UA and then, because nobody at UA could help AT ALL FX USA no answer. Like others here's I found it kinda wonky to make work. Re connects all the time slow re connects ARRRRRRRRRRRGH!!!!!. Then I just started playing with it and found it to be fine if you follow the protocol it requires. I will probably not ever strap it to my barrel because I want to use it to tune for accuracy. Went to the range today and had a great time with this little guy. I was shooting 34KH @940-950 fps, started backing off and found their sweet spot was 100fps less! So then I went to NSA 29.5 FB and 29.0 DB their sweet spot is 951 FPS. WOW I have never shot 100yard groups as CONSISTENTLY as today. My powder burning buddies were really amazed with it and wanted to know if I could shut her up! LOL. The other thing I noticed was when I shot over both FX and the Caldwell, the Caldwell was 15-40fps faster! yet the FX didn't have the velocity swings especially with the slugs that the Caldwell did. I am posting the last shot group of the day you can see it drop off the reg @ shot 15.

Shot count: 22
Low: 912
Hi: 953
Avg: 943
STD Dev: 12.4
Spread: 41.0

6/20/20 12:40:10 PM,953
6/20/20 12:40:27 PM,951
6/20/20 12:41:09 PM,953
6/20/20 12:41:27 PM,951
6/20/20 12:41:34 PM,951
6/20/20 12:41:44 PM,951
6/20/20 12:41:50 PM,949
6/20/20 12:42:00 PM,951
6/20/20 12:42:08 PM,951
6/20/20 12:42:14 PM,951
6/20/20 12:42:37 PM,951
6/20/20 12:42:49 PM,951
6/20/20 12:44:11 PM,951
6/20/20 12:44:33 PM,949
6/20/20 12:44:41 PM,946
6/20/20 12:44:47 PM,942
6/20/20 12:44:53 PM,937
6/20/20 12:45:00 PM,932
6/20/20 12:45:08 PM,928
6/20/20 12:45:14 PM,923
6/20/20 12:45:23 PM,916
6/20/20 12:45:34 PM,912
Great piece of kit as they say!

Thanks for the look



Dennis
 
Hey gals and guys, My intent was NOT to slam the Caldwell unit at all, I just stated that facts. Printed up new range cards last night and will see today how close they are.



Dennis
Click to expand...

Not a problem. You're making a valid comparison. And I might be completely wrong about the accuracy. I base my view on numbers given early in the FX usage that seemed to show many "repeats" as if the unit was not fully measuring small variances in velocity. Even if that is true it still may be showing an "average" that is very accurate. Hard to know for sure but the FX unit sure seems to be convenient and useful for lots of shooters. And I don't have a Caldwell myself.
 
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Hey gals and guys, My intent was NOT to slam the Caldwell unit at all, I just stated that facts. Printed up new range cards last night and will see today how close they are.



Dennis
Click to expand...

I didn't take it that way, just pointing out that if your device is out of specification that you should consider having it serviced especially if under warranty. 954 fps * 0.25%, for instance, is 23.9 fps, so if you are seeing a difference of 40 fps either it's either out of specification, you have a systematic measurement error (not shooting through it straight for instance, measuring as the same distance etc), and/or your FX Chorno isn't the accurate reference you think it is.

You said "I want to use it [FX Chrono] to tune for accuracy" and I pointed out that FX makes not claim of accuracy, so you have no idea what the measurement error is from the readings you get from it. In the launch video that Giles did for it, it showed a measurement error of 1.5% against Lab Radar if I recall correctly. That is large enough to render it useless for your intended tuning purposes.

@Blackpaw said "AEAC compared the FX chronograph to his 4 times the price radar orange one, and this results between the two were very similar." Maybe referring to this one? I took the liberty to index it to the part where he says he was "getting mixed results":

https://www.youtube.com/watch?v=zyb2-eUV8iA&t=26m39s

Steve did not share the raw measurement data just the 30 shot summary at 27:48. It shows a std dev of 3x of the Lab Radar (which claims 0.1% accuracy). You need a reference for each measurement to calculate accuracy.
 
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FWIW the accuracy of a radar unit compared to that of one utilizing two optical sensors is hands down not even comparable provided the light hitting your sensors is consistent...Labradar at its hefty price tag is still only accurate within 1%...where as a caldwell is within .25% as someone else eluded...that is a large margin...and FX's is not published and likely at least twice that of a Labradar, likely nearing 3%...I'd take a friendly over/under wager at 2% :)
 
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All the above seems valid. In general, I would think the FX unit could be used for tuning if one averages quite a few shots for each set point. My concern was, and seems supported by the numbers above, that the FX may not be quite as ultimately accurate as a Caldwell (or other quality optical units) but it's portability is surely an advantage. The question seems to be, what level of ultimate chrono accuracy is needed for useful tuning?

@2D1C-the strings of 951 above (and the multiple 949's) just seem out of place to me. Almost as if the unit may just be repeating a prior readout when the next velocity doesn't vary by at least a certain minimum amount from the previous one. No way to substantiate this, just what it "appears" to be. And it is similar to strings I saw reported when the FX was initially being tested, lots of runs of identical numbers. I know that with my ProChrono unit I get very few "dup" readings but may see 951, 949, 950, dup, 948, 951 or such strings as that. But I guess it is possible that the FX unit could possibly be even more accurate that the optical sensor types, just doesn't seem like it could be so. Especially as it seems to be fairly sensitive to position in relation to bore. Bottom line, if it works for you and you use it more because it is easier to utilize then it's all good.
 
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I got this thing Thursday morning and by mid afternoon I had called UA and then, because nobody at UA could help AT ALL FX USA no answer. Like others here's I found it kinda wonky to make work. Re connects all the time slow re connects ARRRRRRRRRRRGH!!!!!. Then I just started playing with it and found it to be fine if you follow the protocol it requires. I will probably not ever strap it to my barrel because I want to use it to tune for accuracy. Went to the range today and had a great time with this little guy. I was shooting 34KH @940-950 fps, started backing off and found their sweet spot was 100fps less! So then I went to NSA 29.5 FB and 29.0 DB their sweet spot is 951 FPS. WOW I have never shot 100yard groups as CONSISTENTLY as today. My powder burning buddies were really amazed with it and wanted to know if I could shut her up! LOL. The other thing I noticed was when I shot over both FX and the Caldwell, the Caldwell was 15-40fps faster! yet the FX didn't have the velocity swings especially with the slugs that the Caldwell did. I am posting the last shot group of the day you can see it drop off the reg @ shot 15.
Click to expand...

Dennis

I like my FX a great deal

However sometimes things happen with it that I do not understand

Can you provide detail about the required protocol, please?

Thanks

Ed


 
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There is a distance point for the Caldwell to be set at 15-20 feet? I don't recall. In my garage it was like 4 feet in front of the FX so that could be part of it. Also noticed with the Caldwell and the FX the slugs had a much more constant velocity than the JSB KH. Now that said, today I focused mainly on pellets with a variance of 2-20fps I didn't have a POI change at 100 yards that couldn't be called shooter error. % wise? at 900fps 1 or even 2% won't change the POI at that yardage.As for the sequencing I create a profile after connecting shoot a sting, save it copy it or email. I save it. then click "NEW STRING" UNDER "SHOT STRING' and go again. When done go to the last icon (...) click on the saved string and do what you want. Now if yo go to the "rifle ICON your creating a new profile and have to reconnect. That works great for me. @bangd I to got very few "dups" except with , these slugs I never had a triple until slugs. After slowing down the KH's they behaved very well, several moa groups until the wind came up. This superior liner is the very nice!

As bandg stated. It works for me right now
 
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