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HA!- good one, Afro408 -

the 6.5x55 - has an oversized base in comparrison to the normal 57mm case by about .005" to .006" - everyone knows that - but - what does an oversized base do? It increases case capacitiy.

This 'change'(sorry I called it weird) allowed the slightly shorter action of the 94/96 to easily accomodate a case (with long bullet seated) that has quite similar capacity to the 57mm case the Germans used - or so it was written up about the why's and wherefores for the larger diameter, shorter case, some time ago - in Sweden or maybe Denmark by Norma - I do not remember the publication nor author. It may have been some modern writer's speculation or truth - the truth is the case capacities were almost the same.

So - I did what anyone would do (??) - I checked the capacities myself before making asumptions. I am quite surprised no one else did this after I made the statement above and instead just said bullshit because they thought 57mm case held more powder. I am surprised, not upset, just surprised.

Check the case capacities yourselves - length is not everything, my friends.

The 6.5x55 has a capacity of roughly 55.04gr.(water), while the 57mm case has a capacity of roughly 55.55gr.(water) Water is used as it is a standard for case capacities.

Cases are filled to the top of the neck, not bullet base or base of the neck/shoulder junction - top of the neck- for consistancy purposes. They sounds pretty close to me. Yes - the 7x57mm case has 1/2gr. more capacity, and yes - I said approximately or close. Yes - it's technical - but it's true.

Now, the 6.5x55 case had 1/2gr. less capacity than the 7x57 case, but neck the 6.5 up to 7mm and it has the same capacity or even more. That's a shock, A?

Neck up the 57mm case to 8mm and it has greater capacity than the 7x57 - that's normal due to larger neck. Neck up the 6.5x55 to 8mm and it also has more - it's relative capacity and actually the 8mm on the 55mm case has greater capacity than the 8x57, actually - but they are very close.

Which chamber they are fired in, ie: actual size of the chamber, will dictate exactly that their respective capacities will be.

Nice long yearling moose.(year and 1/2 old)

Edited for what I hope, is better clarity.

Edited by Daryl_S (14/07/11 02:14 AM)

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