325 WSM Cartridge Headspace Dimensions

[Jocko]

Can someone inform me if it's known what the SAAMI cartridge headspace dimensions are.

And is this cartridge's headspace measured off the shoulder ?

Looked on SAAMI's website but could not access.

Looking to load some but don't want to bump the shoulders to far.


Thank you

[Hefights]

http://www.saami.org/PubResources/CC_Drawings/Rifle/325%20Winchester%20Short%20Magnum.pdf

This link should get you there, a 400 kb adobe file you can save and print as needed.

[fguffey]

Head space and SAAMI, chamber only.

Can someone inform me if it's known what the SAAMI cartridge headspace dimensions are.

And is this cartridge's headspace measured off the shoulder ?

Looked on SAAMI's website but could not access.

Looking to load some but don't want to bump the shoulders to far.


Thank you

And is this cartridge's headspace measured off the shoulder ?

Looked on SAAMI's website but could not access.

Looking to load some but don't want to bump the shoulders to far.
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Study the case/chamber drawings, the case does not have head space, the case has a length, the length is measured from a ‘datum’ the datum for 325 WSM datum is .445, the .445 has never had a significant to reloaders, not a problem, not understanding ‘datum’ leaves them with purchasing tools that are based on datums, I make datums, I collect datums and on occasions, I purchase datums.

The .445 datum is a hole/round circle drilled perpendicular through a plate, block, etc..

The length of the case is measured from the datum, round hole to the head of the case. SAAMI makes no mention of ‘head space’ as it applies the case outside of listing the diameter of the datum.

For the 325 WSM the length of the case from the datum back to the head of the case is 1.730 with a – (minus of .007”), meaning the minimum length of the case from the datum back to the head of the case is 1.723”.

Then the chamber, the chamber has a minimum and a maximum, 1.726 is minimum, 1.736 is maximum. When reading the footnotes, notice head space applies to the chamber only. Not a problem for me, I off set the length of the chamber with the length of the case.

SAAMI information, I have no clue how SAAMI specifications are going to help you avoid bumping? the shoulder back. My opinion, you first must learn to measure the length of your chamber, not SAAMIES chamber. another opinion, SAAMIies specifications are nice, according to their drawing the chamber could be +/- .005” from 1.731” and the case length could be 1.7265 +/- .0035.

F. Guffey

[Jocko]

Thanks a bunch Hefights - just what I was looking for.