Chronograph Input?

[Osprey78]

Seeing the other Chronograph thread reminded me of this one...

http://www.cabelas.com/product/CALDWELL ... 843418.uts

Does anyone have one? Price point is nice, the app seems to be a good feature and most if not all give it 5 stars on Cabelas, (which I tend to base a lot of my purchases on).

 

[skidmark]

I like the iphone thing.
Competition Electronics ProChrono Digital Chronograph
is what I have though. It was a real wake up to see some of my
velocities I thought would have been faster. And Weatherby
was a bit generous with their numbers too.. :lol:

 

[SneekeeMT]

So I just picked up this chronograph that you have listed here.
First: I have experience running chrono's but have never used this particular one until today'.

First impression: It feels more cheap than the Pro Chronograph that I've used in the past. It's got a lot of nice features and the Iphone app is pretty handy.

The Tri-pod is junk but it serves a purpose.

I received ton's of errors today while using it HOWEVER, I don't blame the chronograph for this I blame the WIND. It was blowing 20-25 MPH from behind me, down range. There was a lot of dust and particles int he air. My guns were filthy and I'm 100% sure that was the cause.

However; It seemed to be reading consistently high. I shot a factory round which I know shoot around 3250 FPS. This chrono read out at 3668!!!

I was shooting my 300 RUM with IMR 7828SSC from 83.3 Grn to 85.7 Grn. Hornady 208 grn A-max:
Following average fps per test group:
3304
3306
3312
3330
3343
3305
According to QL my 85.7 load should be running near 2966 FPS...
Why is this thing going 339FPS faster??? And, why was the factory load 418 FPS faster?

Can anyone explain this.?
Temp was 44 Deg. pressure 29.88In
Chrony was set up 10-12 feet away

 

[jimbires]

So I just picked up this chronograph that you have listed here.
First: I have experience running chrono's but have never used this particular one until today'.

First impression: It feels more cheap than the Pro Chronograph that I've used in the past. It's got a lot of nice features and the Iphone app is pretty handy.

The Tri-pod is junk but it serves a purpose.

I received ton's of errors today while using it HOWEVER, I don't blame the chronograph for this I blame the WIND. It was blowing 20-25 MPH from behind me, down range. There was a lot of dust and particles int he air. My guns were filthy and I'm 100% sure that was the cause.

However; It seemed to be reading consistently high. I shot a factory round which I know shoot around 3250 FPS. This chrono read out at 3668!!!

I was shooting my 300 RUM with IMR 7828SSC from 83.3 Grn to 85.7 Grn. Hornady 208 grn A-max:
Following average fps per test group:
3304
3306
3312
3330
3343
3305
According to QL my 85.7 load should be running near 2966 FPS...
Why is this thing going 339FPS faster??? And, why was the factory load 418 FPS faster?

Can anyone explain this.?
Temp was 44 Deg. pressure 29.88In
Chrony was set up 10-12 feet away

I'd say it's incorrect sensor spacing .
the links in this thread will explain this .
viewtopic.php?f=4&t=29953

 

[SJB358]

I'd bet the chrono isn't open all of the way or the sensors might be a little out of tune..

 

[SneekeeMT]

Jimbires:
Thanks for the link. I didn't see anything on sensor spacing. Maybe I missed it but that thread mostly discussed the barrel mounted magnetospeed chrony.

I forgot to mention that light conditions were optimal. Overcast day and the chrony was level.

 

[DrMike]

I don't believe the Caldwell needs to be unfolded as does the Shooting Chrony or spaced as does the Oehler 35. If it is yielding excessive velocities, it is possible that it is a calibration problem. That would need to be recalibrated by factory technicians. I would verify that the readings are excessive by shooting a cartridge with a known velocity before doing anything else. I know you said the velocity should be known with these loads, but I would shoot a load that was chronographed with a known velocity.

 

[Osprey78]

Thanks for the input guys. SneekeeMT; good luck with the venture.

 

[SneekeeMT]

Well I'm not sure what's up with my chrony. I did use known factory loads that I previously chronoed to test it's accuracy.

I'll say that Caldwell has great customer service. I called them yesterday, explained the problem and they're shipping me a new chrony that will be here tomorrow!

Ill post the results I the new chrony when I get a chance to get it back to the range.

 

[SneekeeMT]

So I received my new, replacement Caldwell Ballistic Precision chrony.....
She's working like a dream! I'm very happy with the new one and it appears to be working just fine. The Ballistic app is great and tracks your shot just like advertised. I recommend this chrony to anyone looking to spend less than $150. Also, used it today along side one of the Magnetospeed chrony's and it was within feet of the same calculated muzzle FPS that my chrony predicted.

 

[Osprey78]

Wow, that's great customer service. Glad it worked out for you. Thanks for the update.