7mm-300 WSM


Well-Known Member
Hi Guys,
Anybody got the finished case dimensions for a 7mm-300 WSM, or know of any literature available.
Cant find anything on the net.
Cheers Steve.
As it’s a wildcat there isn’t a SAAMI drawing. There is for the .300 WSM which will be necked down to 7mm-300WSM.


The 7mm WSM which gives the same ballistics didn’t make it. Too much competition from the 7mm RM, and it has a unique case to prevent it chambering in the .270 WSM. The .270, .300, and .325 WSM share the same case, so it would be easier to neck up the .270 WSM to form cases for a 7mm-300 WSM.



Well-Known Member
The whole essence of the 7-300 wsm is to utalise the longer neck

of the parent 300 case, as the 7wsm has a very short neck due to the shoulder being pushed forward so as

not to allow it to chamber in the 270 wsm.


Well-Known Member
I don't know anything about the case dimensions, but I do know an orthopaedic surgeon specialising in shoulder injuries! :D