Home Forums Hunting & Shooting Ask The Gunwriters Chronograph calibration & accuracy

You guys have clearly taken this to another level. It's kinda weird but I'm picturing you all shooting with tape on your glasses and wearing pocket protectors and camo hats.

Camo hats????


de W7DB, ex K7OWJ

Went metal frame on the glasses but has some kinks from playing with the dogs if that counts.

73, de KF0MD ex KE2KF, gotta sit for the extra if I ever seriously get back into it.

I was gone hunting for a few days, so missed getting in on the beginning of this one, but here are a few observations:

I got my first chronograph, from the Custom Chronograph Company in Washington state, in 1979. It had both breaking screens and light screens, and both provided the same readings. It worked very well but eventually broke down and the company was no longer around. It was pretty slow anyway, since it was the old style where you had to turn a switch and note which lights went on, then translate that into velocity from a table. But it was but was very consistent.

I then bought a Chrony and used it for quite a while until one day I was shooting a .41 Magnum revolver and forgot that one load with 170-grain bullets shoots a lot lower than my normal load with 220-grain bullets. The Chrony was 20 feet from the muzzle, since I was testing a .416 Rem. Magnum on the same day which always caused muzzle-blast problems, and I plunked the Chrony. It did a backflip, and had a hole all the way through the middle.

Replaced it with another, but soon shot it as well. However, this was only with a sabot from a shotgun slug load, which didn't actually put a hole in it. The Chrony people exchanged it for a new one.

So now I am on my 3rd Chrony, and it doesn't work as well as the first. (The second wasn't around long enough to come to any conclusions.) It gives readings that vary 5% or so depending on light conditions, and also misses quite a few shots. Unlike Denton's, it seems to do better on cloudy days, and that has been confirmed since I received my new Oehler 35 from the new batch Dr. Ken is making this year.

So far no shots have been missed by the 35, and I am really liking the proof channel. It isn't nearly as light-condition sensitive as any of my Chronys have been. I also suspect that the 4-foot rail makes precise alignment a necessity, which helps with consistent readings. Life is better.

PS--I have been "calibrating" my chronographs with the same batch of Remington .22 ammo, shot from the same .22 rifle, for many years now. Dunno if it helps or not.

I can't help but wonder if the replacement units they send out are units that someone else returned because they were unhappy with them.

It seems like there are two subgroups of Shooting Chronys. Most of them seem to work just fine. There seems to be another group that just won't behave.

infrared skyscreens and a 16 MHz clock. Available from NECO and expensive, but seems to take care of concerns expressed here. Light makes no difference, can be used in the dark.

I think the shooters location plays a part. Also, a lot of shooters just assume it is reading right.

I don't have any firm "statistical" type numbers but my feeling is the 375 H&H is more likley to read high on a Chrony than other calibres.

As a side note my first chroograph was the Ohler 10, about 1970-71 I think. In Australia at that time it cost about the same as 270 Sako

Just what I've always wanted to hear from someone. Have long suspected that this was the case. Thanks for the post.

If I were to market chronographs, I'd want them to read high. They would sell better because guys could brag about how fast their loads are and no one would be questioning if there was something wrong with their gun or their chronograph. Returns would be very rare.