Gentlemen:
I depart tomorrow for Africa so I should wait and post my question upon my return. But, patience is not a virtue I possess so...

I use a cheap Chrony chronograph and shooting large charges of black powder screws up the readings. I assume the chorny is too close, but is quite small and don't want to move it back too much. I would like to buy another chronograph.

What chronograph would you recommend for bp rifles? Something with a large window to shoot through as I have to set the machine quite a distance from the muzzle so the black powder blast does not mess with the readings.

Also, I just began shooting a .577 howdah pistol and want to shoot safely through the machine at a reasonable distance.

Your suggestions are appreciated.
Cal

I think that the easiest and cheapest thing to try is to replace the rods with either longer rods or longer rods with a dogleg to make a wider bullet pathway and replacing the diffusers with longer pieces of plastic.
I don't know generally how close a projectile needs to be to the sensors but a big ball or bullet should be pretty easy to pick up even a little farther above the sensors.
Not sure, either if the diffuser material matters. A long strip of white poster board or picture matting may even work.

Cal:

I've chrono'd a 577-500 2 3/4" with my LabRadar with good results. The screens on my Oehler seemed to register the smoke and occasional stripped paper patch and would fault.

Dave Manson

a sundial.

That's funny.
I have used my Crony for BP loads quite a bit.
The rods have nothing to do with it; they are just to keep the sun screens up and those are fairly useless too. Just keep the photo sensors out of direct sunlight.
I put Saran wrap over the readout screen so the BP does not embed itself into it and make mess
Otherwise, move it out a bit.
Howda Pistol? What difference does it make what the velocity is? It is slow.

quote:

Originally posted by dpcd:
That's funny.
I have used my Crony for BP loads quite a bit.
The rods have nothing to do with it; they are just to keep the sun screens up and those are fairly useless too. Just keep the photo sensors out of direct sunlight.
I put Saran wrap over the readout screen so the BP does not embed itself into it and make mess
Otherwise, move it out a bit.
Howda Pistol? What difference does it make what the velocity is? It is slow.

Would Saran Wrap between the muzzle and the chronograph keep the unburnt powder/smoke from interfering?

Cal, My first Chrony had the readout screen on the face of the unit. A blackpowder wad took that screen out fairly quickly. My current Chrony has the remote screen, much easier to read. I mounted it on a camera tripod and made two modifications to protect it. First is a strip of galvanized sheet steel as wide as the unit and about 14 inches long. It is sandwiched between the unit and tripod with a three inch 90 degree bend toward the shooter about two inches in front of the unit. This has taken several hits from wads but protects the unit. The sun screen rods I've replaced with 1/8 inch wood dowels, rather one of those take a hit than the original steel rods. I've also marked the dowels with red bands about three inches above the point where they mount on the unit and green bands about four inches above those giving me my OK to shoot limits. I place the Chrony 20 feet from the muzzle, has worked well for me for years.

quote:

Originally posted by Jefffive

Would Saran Wrap between the muzzle and the chronograph keep the unburnt powder/smoke from interfering?

It might, but I would think it would be a PITA changing it between shots.

Thanks gents.
I will purchase the Lab Radar this fall if there is time to do a lot of shooting. Winter is almost here now so maybe wait to spring.
Cal

I suspect you're getting false readings because of all the unburned powder, maybe card wads and whatever else goes flying down range with the shot? I have Pact chrono with the larger, wedge shaped side panels and the opaque top panel.

What I ended up doing and, while it is a PITA, it works admirably, is to tape one sheet of news paper to the front screen, covering the entire screen from top to bottom, side to side. Using blue painters tape it doesn't take long and you can fire several shots through it, always enough to get a good string of readings. It appears to effectively stop the unburned powder and the card wads I use in my BP cartridges.

As I'm a bit late to the party you might have already purchased the Lab Radar. If not, the newspaper has worked well for me and I can't see any reason it wouldn't help others.

Wrecked two of the same chrony's.
BP patch thru the face finished it off.
Had several holes thru the screen from unburnt powder.

I put a square of 1/4" plexiglas in front of the next one. Then damned if I let a 'friend' shoot and he hit one of the metal rods and scrambled that one. "oh damn, sorry 'bout that" Grrrrr!

I'm fully convinced the only reason they put the works in front of the muzzle is so they can sell more of 'em to fools that buy another.

George

Just bought a LabRadar and tested it. It's away for the winter now but what an amazing chronograph. Exteremly accurate, is to the side of the muzzle so it can't get hit by the projectile, wads, etc., easy to set up, and a pleasure to use. come spirng I will chronograph all of my firearms with all of the loads just for giggles. My Chrony will be put up for sale at the spring gun show. I have extra rods and screens in case it gets struck.
Cal