Chrony???
I have the chair gun program I’m wondering with the fps how far from the gun I should set the Chrony to get an accurate reading. I just know if you set the gun a foot or two foot from the Chrony your gonna get two different numbers. What distance is right?
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10 FT. or over as if shooting a rimfire or centerfire gun . The PCP Airgun could be just an inch away when shooting . So what do all of you chrony
pro-users have to say ?
FROM : THE BIRDMAN
I put mine 12″ in front of gun….
No need to spend hundreds jst as accurate as skan pro chrono ect and fits in the gun bag too for use when out in the field only down fall s no printer but can hookup to a laptop
Never had or used a chrony , but I read-up on the PROCHRONY and it stated that if being used by a PCP Airgun the distance did not have to be
10 FT. or over as if shooting a rimfire or centerfire gun . The PCP Airgun could be just an inch away when shooting . So what do all of you chrony
pro-users have to say ?
FROM : THE BIRDMAN
Frankly you should buy the Caldwell Chronograph. It asks for input of the distance from the muzzle and calculates the True Muzzle Velosity as a separate figure.
The last group I chronographed had an average of 916.2 FPS BUT a true MV of 927 FPS.
OH, my setup has the Caldwell chronograph at 5 feet from the muzzle and I entered that distance. So I guess the true muzzle velocity is about 11 FPS faster than measured if at 5 feet distance AND IF THE AVERAGE READING IS ABOUT 916.2.
Checking a lighter pellet, the average FPS was 984.5 but the true MV was 987 FPS
UNFORTUNATELY I cannot enter FPS data to determine the true MV.
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10 FT. or over as if shooting a rimfire or centerfire gun . The PCP Airgun could be just an inch away when shooting . So what do all of you chrony
pro-users have to say ?
FROM : THE BIRDMAN
The reason a powder burner should be a distance from the chronograph is the burning powder can at least cosmatically damage the face of the chrono.
Experience is a good teacher as I let a fellow shoot his revolver over my chrono as close as I was shooting my air rifle. Burning powder put several small marks on the chrono.
Powder burners generally shoot fast enough that 10 feet doesn’t make a noticeable difference.
Example of this is apparent from my shooting my .22 Vulcan at 5 feet from the chrono:
Pellet weight 18.1 gr Avg. chrono reading 916.2 FPS, true Muzzle Velocity 927 FPS.
Pellet weight 14.3 gr Avg. chrono reading 984.5 FPS, true Muzzle Velocity 987 FPS.
That is using the Caldwell chronograph that calculates true muzzle velocity from the measured distance.
I imagine the Ballistic Coefficient is part if the equasion also.