Craigslist score: Chronograph for $60

That's a good one for $60.

exact one I have...good find!

Very nice one....
I have one just like it... but with a pellet gouge in it.... my bad

Major score, great job! Be warned: you may never look at your favorite air guns the same way again.

Hard to believe that you can shoot one but………..I have done it LOL! 

I have a prochrono and a combro.

I started with the prochrono, but found it temperamental regards light and I was never sure it was the same distance from the muzzle.

The accuracy quoted for the combro is excellent and set correctly on the muzzle and it is difficult to see how it can be shot. Cannot be used down range though.

So, I think I have the ideal set up - combro measuring muzzle velocity and prochrono measuring down range (making it possible to measure / calculate ballistic coefficient).

The price of the combro is much less than a prochrono, and small enough to have in your pocket (if you are so inclined!)

I usually shoot from 3-4 feet away or so. Too close seems to cause errors on mine. 1 shot will obviously tell you what speed that pellet went, but shooting a few will allow you to average the highs and lows.

If you want muzzle velocity, measure at the muzzle. Although the difference at 3 - 4 ft will not be significant (Chairgun indicates about 0.1%).

I agree with binfordw, what it displays, is what it is (within the tolerances of the chrono). Any change is more likely the inconsistency of the rifle.

ps a chrono displays, a chronograph records. Many chronos can be connected to a printer to make it a chronograph.

2' minimum distance more for bigger bore rigs or sonner or later you will get false reading from air/vapor/other.


John

There is no visible light emitted from the sensors. The sensors rely on sunlight to operate and the use of the sky screens to shield from direct sun. Sometimes the sky screens need to be left off to get good readings. If used indoors or under a porch roof were there is no sunlight reaching the sensors, an overhead artificial light source will be needed for the chrony to read at all. I use my pro chrono in my gun shop and have the IR screens which have given flawless service.

We're you using indoors or out?

I shoot mine at the end of garage with no sky screen's. So your getting just enough light. I hope no matter where you shoot you have them "prongs" in!

Ha, I just tried to get mine to work I'm the dark last night. I didn't have a good enough light source though, my shop light is out. I tried with a piece of white foam board on top of the wires and a steady light source underneath. Unfortunately I only had flashlights available.

Mine needs a good, sunny day it seems. The times Ive tried to use it when overcast, just seem like a waste of time.

That is true. Overcast tends to be the best for outdoor use. Sometimes getting the chronograph to cooperate can be a bit difficult. Thus far my pro chrono with CE IR screens is the best I have ever had both indoors and out. The IR screens make for flawless performance. They even work at night!!

Pricey yes, but a simple solution for any chronograph. I tried them on my F1 chrony that always gave me trouble and the screens made it work without one single error both inside and out.

Sorry for the sales pitch, but these things are awesome!!