How do you calibrate a chronograph ?

[randyrucker]

Was at the range today working on some loads for my "busted" budget long range precision rifle. I noticed the values I was getting from my Alpha Chrony seemed to be unreasonably high based on the bullet and charge weight. I shot a string of 3 through the Chrony of the guy next to me and they were about 200 fps slower than those clocking out on my Chrony. I'm ready to trash the thing. I have about 100 rounds of data which I have no confidence in. I guess there is no way to calibrate the thing. I guess now I have justification for buying the new V3 Magnetospeed.

[rebel]

I get an F-16 to fly through mine and report back his speed Honestly, I don't know and how do you calibrate a Magnetospeed?

[tallburnedmidget]

Buy me one too!!!

Magnetospeed has some settings to pick up various kinds of bullets to be more precise. You simply pick the setting that most suits your ammo. It comes on the general setting which is suppose to be good for most bullets.

I've never had to adjust mine. I've shot FMJ, PC Cast, Jackted bullets, and all copper with no issues reading

[Jim Timber]

If you're getting goofy numbers you can have light issues or even pick up the specs of powder.

How far away was the unit?

[Klem]

Chronographs are factory calibrated with usually a 5% stated error rate, but you can check it against another.

Put them one in front of the other and shoot over both. Compare the two readings.

[randyrucker]

If you're getting goofy numbers you can have light issues or even pick up the specs of powder.

How far away was the unit?

I always put it 10 feet in front of the muzzle. It has been doing fine until the last week or so. Now it has been reading about 200 fps high. I thought it might be the light or clouds or something like that but I can't nail it down. If I through it against the wall I think it might help.

[randyrucker]

Chronographs are factory calibrated with usually a 5% stated error rate, but you can check it against another.

Put them one in front of the other and shoot over both. Compare the two readings.

Mine reads about 200-220 fps higher than the instructors. He is using a digital pro chrony.

[randyrucker]

I get an F-16 to fly through mine and report back his speed

Once you get over 1000 knots of ground speed you just ask the ATC controller to verify your speed to make them drool.

[dellet]

Did you try fresh/different batteries?

[randyrucker]

Did you try fresh/different batteries?

No. That's a good suggestion though.