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Sidelock
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Thank you, Don. Understandable for even a non-engineer, such as myself.

SRH


"With one foot in the grave ..........and one foot on the pedal, I was born a Rebel" T.P.
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http://www.claytargettesting.com/study2/Study2.2.pdf
Full choke is 25-50 fps faster than cylinder at 4 feet

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Hal Offline
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Doesn't some gas always exit the muzzle before any shot or shot container? I have always wondered if such gas would tend to hold the petals of shot cups closer to the pellets regardless of choke.

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That's a good question, Hal. I know that seals in hydraulic cylinders that are shaped with a lip, similar to the bottom of some shotcup's rims can contain thousands of psi in liquid. I have kinda always assumed that they do a far superior job of sealing off the gases than the old card/fiber wads did. But, do they completely contain it, 100 percent? IDK.


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There was a Gun Digest article by a Danish engineer in the early 90s, on how choke works. It was awarded the editor's prize if I remember right. It stated that shot is affected by choke in a similar manner that water is affected by a constriction on a hose, making the central core of the shot fly out faster. This is an oversimplification from memory, the article had lots of diagrams showing the choke effects on shot and very long text analysis.

The "squeeze" theory seems to be supported by high speed photos of ammunition makers showing shot from choked barrels exiting the muzzle in a long string, contrasting sharply with the short fat columns exiting cylinder bores.

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Ed Lowry, American Rifleman, "The Effect of Shot String", November 1979

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[Linked Image from photos.smugmug.com]

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Hal Offline
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Would be interesting to pick up some used shot cups and check for 'leaks'. Should also show up on high speed photos.

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