Maximum distance A Chrono Can Be Setup At A Match?

[szhttm]

Hello;

In looking through the USPSA rules, I found Appendix C2 and number 3 where it states:

3. In all cases, the skyscreens must be positioned and spaced per the manufacturer’s

requirements for the chronograph in use. The closest skyscreen must

be placed no less than 10 feet from the shooting location.

Are there any rules that state how far away it can be placed from the shooting location?

Thank you!!!

Good Luck And Be Safe!!!

[JaeOne3345]

All I know is that CED chrono at the Nationals this year was veryyyyy unforgiving. LOL.

[Skydiver]

I don't think there is a maximum distance, but the other rules in the same appendix do require that the chronograph be "calibrated" properly. So as long as they are reading correctly and consistently for the calibration ammunition when initially setup (and on the succeeding days for single chrono setups), then it's good to go. From what I understand, most conscientious chrono officers do take pride in the setup and accuracy of their chrono setup, so they have a vested interest in providing the best service they can during a match.

[szhttm]

Thank you!!! I was trying to find out what the best distance would be to chrono my reloaded competition ammo. I think if I setup it up at 15 feet away from the shooting area then I should be ok. I might even setup it up at 10 feet and then 15 feet away just to see if it makes any difference at all.

Good Luck And Be Safe!!!

[EkuJustice]

I would check with Ken Skeeters. He has run a few chronos in his day

[jwhittin]

I would defer to the equipment manufacturer's instructions. It may depend somewhat on the technology. For my photo sensor type chrono it states a minimum of 10 ft between the muzzle and sensor for high velocity rounds and at least 5 feet for slower velocity rounds. For practicle distances like 10ft to 15ft, its not going to make any difference in measurements. At matches I've shot that use other types of sensors, they still ran about 10 to 15 ft between the muzzle and the first sensor. The second sensor was another 3 to 5 feet farther away.

Biggest factor is the measurement statistics and how you load to meet PF. As a general rule, my loading velocty is the required velocity plus 2 time the measured standard deviation (there is a good reason its not 1 or 1.5). This gives my a high degree of confidence that even with unknown factors, I'll be able to pass. Kinda drifting off the main topic but thought it was worth mentioning.

[9146gt]

I never did get a good answer from CED when I sent my chrono in for FPS issues between the sky screens and the infared screens. Calibration was done with an air soft pistol indoors with a known FPS and then checked outdoors with .38super reloads.

Tom

[pjb45]

The Chrono at most major matches has a blast shield in front of the first screen. This will help give you the most consistent reading.

I set my Chrono up to be around 10 feet. I am usually within a PF of 1 at Nationals or Area 2.

[bofe954]

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Edited November 5, 2012 by bofe954