How does a chronograph work shooting

You can also experiment with for example , , and grain bullets to develop loads where heavier bullets are faster than lighter bullets. With my chronograph, I get so much more from my range time than just punching holes in paper!

I have usesd a ProChrono for several years. For my purposes it is cost effective. I use the baseline caldwell chronograph. Bought some extra rods and sunshade from their website. I have found it accurate and reliable. Also, tough as nails. The front is currently wrapped in mossy oak duct tape after receiving a direct hit from a barnes grain tsx in.

I reset the chrono and it kept on working even with a sizable hole through it. It is a must have for reloaders. The book velocities are A: just what they got from their barrel in their test lab. B: A starting point. Time limit exceeded. Leave a Comment Your discussions, feedback and comments are welcome here as long as they are relevant and insightful. Please be respectful of others.

We reserve the right to edit as appropriate, delete profane, harassing, abusive and spam comments or posts, and block repeat offenders. All comments are held for moderation and will appear after approval. You do not have to put a target downrange, but it may help some people to shoot over the screens not into the Screens.

The screens are normally mounted on a camera tripod downrange. Because the screens will measure anything that changes the light level setting up is critical. If you set the screens too close to the bench the front screen can pick up the muzzle blast as well as the bullet. When shooting subsonic ammo, the muzzle blast will reach the first screen before the bullet. As a rule most chronographs with separate screens have about metre cables.

Set the screens so the furthest screen is near full cable length away. The folding Chrony should be set at least 3 metres away, and increase this if gives an error with muzzle blast.

The light level should be the same for each screen, not one in sun and one in shade. For full sun use the covers over the screens, for overcast days you can leave them off. Most factory light diffusers or covers are very narrow, and you have to be careful not to allow direct sunlight on to the lens of the screen, wider covers cut from white core flute have worked very well on a number of different chronographs.

Knowing more now, I load for factor and if I see a poor chronograph set up, I have the knowledge to challenge it. So how do we prove a chronograph for a competition? Loads developed which are near maximum velocity during cold weather may produce dangerously high pressures and be unsafe during hot weather.

Temperature of the barrel and the ammunition itself. The same with the ammunition. Different altitudes may also affect velocity. This is also true with flying, velocities can vary for up to three days after air travel.

Battery — A good power supply is needed, usually a fresh alkaline battery. Low voltage will give poor or no results. Alkaline batteries hold the voltage better the carbon batteries. Lighting — MUST be balanced on both sensors. If the sun changes position, you must maintain a balanced condition on both sensors. Whether in bright sunlight using the top screens or on shady days in which the top screen is optional , it is critical to maintain a balanced situation on both sensors.

In bright conditions do not allow direct sunlight onto the sensors. You see, depending on time of day, time of year, weather and — I swear — phase of the moon, the screens will be more or less sensitive to a bullet's shadow. In the shade, they pout. Indoors, they get psychotic, as fluorescent lights make them crazy.

The allowable area above the screens, where a bullet can pass and be "seen," changes not just from day to day but hourly and even minute to minute. If you injure a Shooting Chrony, you'll have to submit a photo of the damage. The manufacturer will reply in return with a quote for repair costs.

You can be hunting again and again for the sweet spot where readings come regularly. This is the "chrono dance," and you do it unless you build a special box wired for outlets to hold your screens with incandescent lights over them. That's a box that is hard to schlep to and from the range each time you want to check bullet velocities. I deeply envy range labs that have built-in shooting chronographs such as this. Add to the dance festivities the varying bore-to-sight distances of different firearms, and you can have bullets passing perilously close to the equipment, even skipping off the edges of them.

The imperative of manufacturing does not always mean the same thing. Some companies use separate sensors, remotely wired to the calculating box with its readout. Others put all of it in one unit: sensors, hardware, batteries, readout. That's when the real fun begins. It is one of the "all in one" designs, with sensors, hardware and readout all in one plastic tube.

It was drilled end-to-end with a very nice 9mm entrance hole and a larger exit. When we picked it up, parts rattled inside. Replacement parts for Oehler Skyscreens are available at regular price. Even after taking a direct hit, this Model 35P still works. The shooting chronographs with separate sensors fare a little better but not always. You still have the overhead shades and the legs that hold them.

Plus, you have the screens themselves, small plastic boxes about the size of a pack of cigarettes. It has the electronics on a bench-top box, and the screens, affixed to a rail on the tripod downrange, have attached cables to signal the clock. I had gone to the trouble of fabricating a plywood screen, a short wall with a hole through it, to keep the muzzle blast from toppling my chrono on its tripod. This worked well, but then I started checking the speeds of the various slug loads.

After a few shots, I got the dreaded "No stop signal detected" showing on the readout. I peered over the plywood barrier to discover a lack of screens, legs and shades. The plastic carnage generated by the sabots was impressive. Yes, the sabots were "only" pieces of lightweight plastic, but they were hard enough and traveling at some 1, fps, and they scraped all the chrono hardware off the top of the base rail, leaving it bare on the tripod.

The expensive hardware was fine, but the day's work was done, and I still had to buy new screens and shades. The next time I was chronographing shotgun loads, I had an improved plywood shield and spare hardware.

One very compact shooting chronograph design is the Shooting Chrony.