[Jack Monteith]

Hi, Carroll:
My Chrony is a dozen years old, so the new ones may be better, but your setup sounds like a tricky one for any chronograph. Setting up on a table is no problem. Lighting might look OK, but a light meter might tell you otherwise. You may need Chrony's lighting kit and a place to plug it in. How far back can you get? I prefer 10 feet and 5 is about minimum. Otherwise muzzle blast can damage the unit or muzzle flash can trigger false readings.

From what I've heard the reconditioned units are OK and they've got a 1 year warranty.
http://chrony.ca/

Bye
Jack

 

[Jack Monteith]

Hi, Gents:
If I had to chronograph at 2-3 feet, I'd try doing it the way the big boys do, and put a blast screen between the muzzle and the Chrony. Sierra #4, page 590 shows a 1/2" sheet of plywood with a small hole for the bullet in place. A foot square piece of plywood and a couple of 1 foot 2X4s should do.

My old Chrony has problems with conicals from the flinter shaking it up. Suprisingly, full snort .30-06 loads don't brother it. It has the old cardboard diffuser stands with a 2" wide by 4" high hole to shoot through. This puts the bullet about 4" over the sensors. The solution is to shoot on an overcast day and shoot over the stands without the diffuser screens. That puts the bullets 9-12" over the sensors. It reads .22 Long Rifles fired that high, so there's no problems with .50 calibre conicals.

Once I was shooting round balls and got the error sign. Checked the chrony and there was a patch sitting on the rear sensor.

I'd like to set an F-1 Master up at 100 yards or more, with a foot square slab of 1" thick steel I've got in front of the sensitive parts, just in case. Reading the velocity at that distance is no problem with the old 6" Newtonian star scope.

Bye
Jack