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Old September 21, 2010, 10:56 AM   #16
mykeal
Senior Member
 
Join Date: October 8, 2006
Location: Northern Michigan
Posts: 2,772
Doc,

You restated my thoughts accurately; thank you.

Just a short dissertation on chronograph operation in general, in response to another member's assertion:

Chronographs actually measure only time; they then calculate and display velocity. And yes, it is the vector quantity velocity and not the scalar quantity speed. The vector that's calculated may or may not be a component of the projectile's vector - that depends on whether or not the projectile is traveling a path parallel to the chronograph's axis of measurement. If it's not, the calculated vector is simply a component of the projectile's true velocity and thus one of the many possible errors.

Doc, you are absolutely correct that the internal calculation of velocity from the empirically derived time value is extremely accurate in even the least sophisticated chronographs.

I don't have any experience in actually setting up a chronograph, but how well it's measurement axis is mounted with respect to the projectile's velocity vector will have a great deal to do with how accurate the results are. Is that easy to do? Just putting the bullet through the wire loops isn't enough - you need to be sure the axis is properly aligned. This may or may not be an issue - I don't know.

And one final observation. On another forum, dedicated to traditional muzzleloaders (which means they eschew in-lines and cartridge bp shooting) there is a large (over 10,000) group of well seasoned practitioners who are fans of the Dutch Schoultz's Black Powder Accuracy System. I've used it myself and will guarantee you it results in simply stunning results: 50 yard 3/4" 5 shot groups repeatedly and consistently. It's essentially a method of working up the best load (ball, patch, powder and lube) that works in your rifle. It costs $20, and you have to burn a lot of powder and spend a lot of time preparing for each shooting session, but the results speak for themselves. And nowhere in the system is a chronograph even mentioned.

Last edited by mykeal; September 21, 2010 at 11:06 AM.
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