My Chrony

[Steve Ladino]

It seems to me that my velocities are very high according to my Chrony readings. Have you guy's experienced a systemic decrease in accuracy from your Chrony's over time? Mine is about twelve years old and i no longer use the sky screens but just align the Chrony about four inches or so below the bore axis. Mine is in good condition, never met the bullet and acts as it always did?
Thanks
Steve

 

[jlow]

I think it is always problematic when you use the chrony without the sky screens as they really only work that way when it is cloudy. If you think it is off, you can test it with loads of known velocity and if it is bad, you can send it in for calibration.

 

[amlevin]

My chronograph with Infra-red sensors always gives me speeds 100 fps or more faster than expected. In my case it's not the chronograph but a barrel that is very "fast". I've used a box of factory ammo with the same bullet weight and shot it over the chrono using two different barrels. The "old" barrel matched the speeds marked on the box of the factory ammo and the new Benchmark barrel shoots them almost 200 fps faster, again with the same ammo.

I'm having a hard time worrying about the extra speed when the charge weights of my loads are almost 2 full grains under the published max for the bullet/powder combo, the groups at 300 yards are sub .250MOA, and there are no pressure signs on the cases. Also, the bullet drops at various ranges match the ballistic's calculations from my external ballistics program.

Sometimes you just get a barrel that "brings it all together" and bullets go a lot faster than in the barrel they used to gather the data that was published for your powder.

 

[lpreddick]

i'm on my THIRD chrony now...shot the other two by accident. i kept gettig strange mvs , so i kept shooting lower to the sensors not realizing my scope was 2+in above bullet path. i strung an aiming j point 3 in above the sensors and usually get "real"mvs but still get ones that are not possible. currently i'm connectng a battery several hours before going to the range, then changing to a new one then. i like the idea of having a load that measures true and maybe using it as a test load before and during load development.

 

[thekriebles]

I have not had any issues with an older Oehler model 33 or an earlier version model 35P.

 

[jlow]

This is my setup. Nothing fancy, just the blister pack that came with the Cabela's laser boresighter stapled on a piece of cardboard and that to a flat piece of wood with a hole and a large washer hot glued to the bottom. Here it is mounted on the gun. I use the blister pack because it keeps everything together for protection, travel, and it and the blocker is never separate and reduce your urge to not use it.

The cardboard when you put the laser in your barrel and the laser through the hole in the piece of wood completely blocks you sight picture if you forget and decide to shoot. That large washer is just a weight to make sure the setup is standing straight up.

Using the laser boresighter significantly reduce your chance of hitting the chrony. Since I use a Ohler 35P, I really do not want to shoot it plus this helps me to center where the bullet will pass over the detectors.

 

[amlevin]

i'm on my THIRD chrony now...shot the other two by accident. i kept gettig strange mvs , so i kept shooting lower to the sensors not realizing my scope was 2+in above bullet path. i strung an aiming j point 3 in above the sensors and usually get "real"mvs but still get ones that are not possible. currently i'm connectng a battery several hours before going to the range, then changing to a new one then. i like the idea of having a load that measures true and maybe using it as a test load before and during load development.

I've found that lighting is a major issue with most chronographs that rely on ambient lighting.

Since I live in a area where "sunshine" is often just a word in the Dictionary or mentioned in a weather forecast for a distant city, I invested in a Chronograph that utilized the InfraRed Sensors.

I can use my chronograph on any day I choose as long as it's not raining and get nice reliable readings no matter what the ambient light situation is. Others who come to the range to chronograph their loads often sputter and cuss because they either get NO readings or the readings they do get are in the "you've got to be kidding" category. One shooter has gone through three chronographs, all different brands, in the last year. Even something as simple as a couple of LED strips from an auto parts store, taped to the top of his sky screens, and powered with a couple of lantern batteries would have cured his problem but he thought it would look too "Mickey Mouse".

Unless you have I/R sensors then you'll need to deal with lighting issues. Not just light, but steady light.

 

[wyoming .260]

i'm on my THIRD chrony now...shot the other two by accident. i kept gettig strange mvs , so i kept shooting lower to the sensors not realizing my scope was 2+in above bullet path. i strung an aiming j point 3 in above the sensors and usually get "real"mvs but still get ones that are not possible. currently i'm connectng a battery several hours before going to the range, then changing to a new one then. i like the idea of having a load that measures true and maybe using it as a test load before and during load development.

I've found that lighting is a major issue with most chronographs that rely on ambient lighting.

Since I live in a area where "sunshine" is often just a word in the Dictionary or mentioned in a weather forecast for a distant city, I invested in a Chronograph that utilized the InfraRed Sensors.

I can use my chronograph on any day I choose as long as it's not raining and get nice reliable readings no matter what the ambient light situation is. Others who come to the range to chronograph their loads often sputter and cuss because they either get NO readings or the readings they do get are in the "you've got to be kidding" category. One shooter has gone through three chronographs, all different brands, in the last year. Even something as simple as a couple of LED strips from an auto parts store, taped to the top of his sky screens, and powered with a couple of lantern batteries would have cured his problem but he thought it would look too "Mickey Mouse".

Unless you have I/R sensors then you'll need to deal with lighting issues. Not just light, but steady light.

I have found the exact opposite problem here, I have used black markers on 55 gr. .243 bullets @ 3900 plus just for the chrony to find them,. Here a cloudy day is usually better and with sky screens in place.

P.S. we had trouble with a Chrony that was reading high speeds . If it is not completely laid flat or opened all the way the distance between the sensors is different and the tech guy said you gain 75-80 ft per sec. for every .10" you lose. Made sense and now I struggle with a set up at all. I do better getting velocity with a combo of readings and shooting and comparing drops at distance. Not good for working out es and sd , but makes you a better shooter............ Just my humble opinion.........

 

[amlevin]

Here a cloudy day is usually better and with sky screens in place.

A cloudy day in my part of the country means not enough light to use a chronograph without putting it in a lighted "coffin", using auxilliary lights like are sold for the Chrony's, or I/R sensors. The cloud layer gets thick enough where the photocell controlled yard lights turn on.