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Unread 08-12-2009, 11:59 AM   #9
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John D.
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Hi Kevin,

Actually - the way I understand it - given the elasticity of brass - it will "shrink" a bit upon release of pressure, although not to it's original size (fire-forming is a perfect example!). By comparison, steel will not "shrink", and for example caused some problems during wartime manufacture of steel cased ammo in even some straight walled rounds (.30 carbine) as steel doesn't have the elasticity of brass, so would cause extraction issues.

Anyway - I could be wrong - and often am..

John

Quote:
Originally Posted by Kevin McCormack View Post
John;

I have never heard of a cartridge (rifle or shotgun) contracting once it has been fired. It doesn't make any sense what with all the pressure, heat and expansion of ductible materials (think of "fire-forming" rifle brass in chambers slightly larger than the designed-for cartridge in order to expand the case to fit a larger chamber).....
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