My current crony is number III
A little chronograph history is in order here...
The sensors ARE the skyscreens. The frosty white plastic pieces that are held over the top of the sensors by the rods you shot are sun screens, or sensor shades, or diffusers. In terms of the light seen by the photosensors, the shades provide a constant background, whether sunny, cloudy or partially cloudy skys are present while you're shooting, thereby improving the accuracy of your readings. In the "old" days, chronographs did not have photo sensors to catch the shadow of the bullet as it passed. They had thin pieces of paper or plastic with, literally, a "screen" pattern of imprinted conductive material on each side that went left - right on one side and top - bottom on the other side. All the traces on each side were connected so as to form a single circuit, with the circuits on both sides connected to each other. When viewing through them they looked a bit like window screen. These "screens" were electrically connected to the timing circuit. A bullet could not pass through the "screen" without breaking the circuit trace on one or both sides, thus activating the timing circuitry. The drawbacks to these screens were: 1.) They were expensive and had to be replaced after each shot. 2.) You couldn't shoot for group while testing your velocity because passing through the screen disturbed the bullet flight. Dr. Ken Oehler developed the "Sky Screen"(TM), using photo sensors illuminated by the sky and activated by the bullet shadow passing over them, to give us what we have today, a "sky screen" that doesn't need to be replaced after each shot and which allows us to shoot groups while chronographing.
You should have kept the "fast" one. Think of all the bragging you could have done.
=============================
I can't afford to shoot mine. I suppose I COULD scrape up the money for a replacement or for repairs, but NOT shooting it is FAR cheaper. With that mindset, I've spared my Chrony the pain and embarrassment of being shot. See post #26 on page 2 of this thread.
Regards,
Stew
Last edited by AZ-Stew; 09-05-2010 at 07:27 PM.
Sig file change:
"Obi Wan Baloney"
VOTE 2012! Throw them out! Every last one of them! (Feel free to add this to your sig. Spread the word!)
"...Get a rope." Pace Picante Sauce commercial, ca. 1984
"I (did, on several occasions) swear to support and defend the Constitution of the United States, against ALL enemies, foreign AND domestic, and to bear true faith and allegiance to the same." And when I left, they never asked me to recant.
Interesting history there, Thanks for sharing!
While i have a chrony, i haven't used it to test any load yet.
It remains in the 'yet to be shot' catagory so far.
I aim to misbehave.
Mostly Harmless.
[QUOTE=AZ-Stew;800406]
A little chronograph history is in order here...
The sensors ARE the skyscreens. The plastic pieces that are held over the top of the sensors by the rods you shot are sun screens, or sensor shades. In terms of the light seen by the photosensors, the shades provide a constant background, whether sunny, cloudy or partially cloudy skys are present while you're shooting, thereby improving the accuracy of your readings. In the "old" days, chronographs did not have photo sensors to catch the shadow of the bullet as it passed. They had thin pieces of paper or plastic with, literally, a "screen" pattern of imprinted conductive material on each side that went left - right on one side and top - bottom on the other side. All the traces on each side were connected so as to form a single circuit, with the circuits on each side connected to each other. When viewing through them they looked a bit like window screen. These "screens" were electrically connected to the timing circuit. A bullet could not pass through the "screen" without breaking the circuit trace on one or both sides, thus activating the timing circuitry. The drawbacks to these screens were: 1.) They were expensive and had to be replaced after each shot. 2.) You couldn't shoot for group while testing your velocity because passing through the screen disturbed the bullet flight. Dr. Ken Oehler developed the "Sky Screen", using photo sensors illuminated by the sky and activated by the bullet shadow passing over them, to give us what we have today, a "sky screen" that doesn't need to be replaced after each shot and which allows us to shot groups while chronographing.
I wasn't aware that that sky screens had to be on if it wasn't in direct sunshine?
Bob T
I assume you mean the sensor shades.
They don't HAVE to be, but if you get false readings or errors without them, put them on and I'll bet you you'll get more consistent readings. The photocells don't pick up the bullets as well against a blue or cloudy sky as they do against a consistent white background.
Regards,
Stew
Sig file change:
"Obi Wan Baloney"
VOTE 2012! Throw them out! Every last one of them! (Feel free to add this to your sig. Spread the word!)
"...Get a rope." Pace Picante Sauce commercial, ca. 1984
"I (did, on several occasions) swear to support and defend the Constitution of the United States, against ALL enemies, foreign AND domestic, and to bear true faith and allegiance to the same." And when I left, they never asked me to recant.
Well I saw my first kill today! A wad from a Four Bore rifle (just over a 1" bore)killed it.
Last edited by AkMike; 04-03-2011 at 04:59 PM.
If Obummer is the answer, How stupid was the question?
Freedom is never more than one generation away from extinction. We didn't pass it to our children in the bloodstream. It must be fought for, protected, and handed on for them to do the same, or one day we will spend our sunset years telling our children and our children's children what it was once like in the United States where men were free. -----Ronald Reagan
well folks, me thinks it's time to buy shares in the chrony company.
jb
I tried to take my chronograph out the other day and it jumped out of my arms and went and got back in its box.
Melting Stuff is FUN!Sent from my PC with a keyboard and camera on it with internet too.
Shooting stuff is even funner
L W Knight
My fathers friend took us woodchuck hunting, stopped the truck and jumped out and quickly set-up across the hood of his truck to shoot at one in the field. At the shot, a very neat crease appeared across the hood of his truck. The rifle had seethru mounts for the scope. OOPS! My dad never let him live that one down.
I was shooting with some friends when one of them shot his chrony. He wasn't too impressed, but laughed and said, "that's the second time I've done that". It seems as though once would be enough.
My chrony is alive and doing well. I have to promise it that i will not shoot it before it will come out of its box. My chrony once stood brave and would not flinch as i shot,but one day i messed up and it saw my target after shooting. Now it stands scared and shivers as i shoot. I think that this is what causes the erratic reading some people get when using one. Your chrony must have confidence in your shooting before it will become accurate. Dont ever let someone else shot through your chrony, or it may end up mounted on the wall next to the button buck. Do people exaggerate the size of their chrony when telling the story of their recent kill?
It is with sadness, I must announce... that my chrony was murdered.
It was shot in cold weather with a 9mm subcompact. The offending round was fired by my friend. The conversation went something like this:
"Hey, don't shoot my chrony."
*blam, blam...
"I shot your chrony."
RIP
wow,, self full-filling prophecy there.
I bought my first chrony about 1991 or '92.
On the first trip out with a friend and his new SP-1 Colt he begged me to let him try the chrony, first round and my chrony was DRT. Center punch killing shot and my friend slowly lifted his head off the stock and said,, wow,, sorry.
He had ignored my admonition to shoot high since the sights were well above the barrel of the AR.
He did reach into his wallet and give me $40.00 to send it in for R&R on the spot and so far I have not shot it myself,, knock on wood.
Boolits= as God laid it into the soil,,grand old Galena,the Silver Stream graciously hand poured into molds for our consumption.
Bullets= Machine made utilizing Full Length Gas Checks as to provide projectiles for the masses.
http://www.cafepress.com/castboolits
castboolits@gmail.com
As with all the other tale's .... year's ago , shooting with a friend .... then I had a 68 El Camino , my pride and joy ... my friend set up his scoped 22 mag rifle resting on the drivers side of the bed and aimed across it to the target area .... everybody here know's the outcome ... boy was I yelling at him for a while.
Later on after a few beers we were laughing about it but for many years after that chevy still had that nice neat little hole in the chrome trim as a conversation piece ......
Got to get one of those Chrony's ......
I replaced the metal poles that hold up the shades with 1/8" wooden dowels that are painted fluorescent orange after knicking one with a CB 150 RN 30-30. It makes a huge difference in the sight picture for me although a Female friend did just wing the rear left hand outside steal case with a 38 Special. I still don't know how she managed to hit it there but glad she didn't hurt it. So now the only one that shoots thru the orange sticks is me. And that's how it's lasted as long as it has. Great to know that the replacement parts are not too pricy.
I know a guy, (BTW I will never hunt with him)… He put two holes in the passenger side bed of his truck shooting at a deer while resting his rifle on the drivers side.
While I have stuck g/c's into the housing of the front skyscreen and coasted a boolit through the top edge of the housing (knock on wood) I have yet to kill one. (Now watch, I'll burn it to the ground testing tomorrow.)
Sight alignment, sight picture, squeeeeeze....
bullseye!
Dwight
Well I just had to join the club Saturday. Mine took a 9mm slug at around 1175 fps.
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |