WENT TO MY RANGE IN NO-MAN'S LAND (BETWEEN THE RIO GRANDE AND THE BORDER FENCE) FRIDAY, SATURDAY AND THIS MORNING (SUNDAY 6/23/19), TO CHONO A BUNCH OF 45 COLT LOADS AND SOME 480 RUGER LOADS, USING A CHONY. SET UP THE CHONY 15 FEET AWAY, TEMPERATURE ALL 3 MORNINGS WAS IN THE LOW 90's, AND WINDY (AROUND 20mph) ALL 3 MORNINGS. FRIDAY AND SATURDAY MORNINGS IT WAS OVERCAST AND I WAS AT THE RANGE LATE MORNING. FRIDAY AND SATURDAY I GOT NO "ERROR" READINGS NOR DID I GET ANY WEIRD READINGS, FANTASTIC CHRONO DAYS. THIS MORNING IT WAS ALSO OVERCAST BUT PATCHY, LOW 90's AND WINDY, BUT ABOUT AN HOUR EARLIER IN THE MORNING, AND MAYBE A LITTLE WINDIER, SO WHAT HAPPENED? ALL "ERROR" READINGS, OUT OF AROUND 10 TRIES ALL "ERROR" READINGS, WTF! CHRONOGRAPHING CAN DRIVE YOU NUTS!

AFTER FRIDAY AND SATURDAY's SESSIONS I THOUGHT WINDY, HOT AND OVERCAST WERE "IDEAL" CHRONOGRAPHING CONDITIONS BUT THEN THIS MORNINGS FIASCO. SO WHAT ARE IDEAL CHRONOGRAPHING CONDITIONS, TIME OF THE DAY, ORIENTATION TO THE SUN, etc.?

A few things that will completely jack with a chronograph are bright/direct sunlight and also if it?s too close to a big bore gun. The muzzle blast has to really dissipate otherwise the chronograph will give an error reading. I set mine a minimum of 25 feet in front of my 460 and always do it in the shade or overcast days.

One more thing comes to mind. If you have an error reading, I?ve found that treating it like a computer sometimes works. Without moving it, I?ll completely shut it down, let it sit a minute or two, then ?reboot ?.

Lastly and while it hasn?t come to this YET, I?ve come dang close to putting a bullet through mine and be done with the mental frustrations involved with trying to be the Rain Man of ballistics...

USPSA/IPSC can not afford to have an error when checking competitors ammo for power factor. So they build a box and provide artificial light that comes from all directions, this allows for very controlled conditions and accurate readings.

I have gotten within 2-4 power factor points of their method consistently by chrono in the shade of an awning or overhang, basically providing light from all directions. The key for me is never chrono when conditions allow for a hard and distinct shadow,....overcast days are perfect or provide your own shade.

Trapr

I swore my Chrono was broken last year ... errors all over the place. Didn't seem to matter what the lighting was. So, I broke it out this year and it seems to work when keeping it in the shade. I've taken to firing .22's through it with the camp rifle to check it out before wasting handloads I need to check. Last time out I got a few errors and I'm beginning to think Randy is right, muzzle blast causes problems.

P

Magneto Speed has none of those concerns. It'll read in hot, cold, night, day, rain, sleet, snow, shade, light.....take your pick. I have never had mine drop a shot yet.

http://www.magnetospeed.com

Mine is set up as a remote unit with no barrel attachment needed. It is mounted to my rest. So, it does not require a shaky tripod. Being mounted to the rest & ultimately adjustable it meets all of my needs.