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Old 11th March 2013, 09:34 AM
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Ceathreamhnan Ceathreamhnan is offline
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Join Date: Nov 2011
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A scope tube made of 6061-T6 aluminium will have a linear thermal coefficient of expansion of 23.4 ppm/DegC, which is the same as saying 0.00234 %/DegC.
So a scope that is 300mm long will expand by 0.155mm in a change of 40 F or 22.2 DegC (going from 4 Degc to 26 Degc, say).
This is aircraft aluminium, so for comparison, a Boeing 747 that's 231 feet long would expand 1.43 inches. This would be 12.9 inches if the math quoted above were correct, I think.
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