How to correcly chrono?

I happen to use a single light bulb suspended four feet above my Chrony halfway between the back and front sensors. I haven’t tested it, but I’m hypothezing that the higher a single light source the smaller the lighting angle between the sensors (closer to perpendicular over each), and thus the more accurate the readings. There might also be the case of when a single light source is coming from either side (from left or right of the chrony) of the line of sight; and also of when the single light source is coming from above but back or front of the Chrony. So in my mind I’ve been picturing the single lighting source as a point above the Chrony and then the changes in the angle created by the two rays traveling to the two sensors as the lightbulb is lowered/raised, moved to the left/right of the chrony, or moved to front/back of it.

I’m thinking one dedicated light (LED’s as have been suggested) directly above for each eye, even shading each eye from the light of the other. I’m thinking about lighting since I chrony (my 24″ barrel, .22 Condor) from inside my garage and shoot at a target out the back door. I’d welcome your thoughts on this.

[I received my Cometa Lynx on June 6th, and quite honestly ( I quickly filled it to 200 bar, scoped it, chronied it as I shot the first 10 shots out of the box) I had to walk to the paper target at 22 yards to see if something was wrong, because through the scope I wasn’t seeing any thing happen to the first hole. This was 18.1 JSBs at 855 to 860 fps. I’ve been busy building a multi-dimensional work table for my tools and machinery. I’m away from home for about two more weeks. But when I get home and finish my project, I’ll be setting down to shooting the Cometa some more and at further ranges and different regulator settings. Steve at Pomona Airguns sent me one that already had the seal issue fixed.]

Two things to remember, if your angle is off, meaning your not shooting level over the screens, your reading will be slower, due to the pellet traveling further, it will never read faster.

However, if you have your Chrony attached to a tripod with the 1/4/20 screw they use, your CHrony may not open fully, making the distance between the sreens shorter, this will result in a faster reading.

Also remember that every chrony is different. My Chrony reads higher than what the XPAirguns shop reads, they run two I believe, in a windless room.

I set my chrony up now and the standing measure the muzzle distance over level screens. Then I go back 20 feet and sight over the level chrony screens to a point on my backstop, a huge Doug Fir, and pick as a target a spot that is the same distance over the level screens.

A better way would be to have two shooting benches one for the chrony and target, one for your rifle, then measure the muzzle over the chrony and measure a aiming point.

But, I also double check my velocities by measuring tragectory against Chairgun at the velocities I record, sighting in at 50 yards and at 1oo yards and measure the drop.

I get a chuckle out of those who state their gun shoots hard because they can feel or hear the difference, or shoot into wood to get an idea of velocity.

Regards,

Roachcreek

Be consistent.