458 SOCOM and 50 Beowulf (12,7 x 42) specs (SAAMI or other)

A friend of mine is looking for dimensional data for these two cartridges according to their:

– cartridge dimensions
– reamers
–chamber dimensions

I read that many refer to the SOCOM as a SAAMI cartridge, but I can’t locate it in their database

12,7 x 42 is the metric name for a cartridge that is identical to the Beowulf, and used to avoid “copyright troubles” since “Beowulf” is a registered trademark

Any help will be appreciated

Here are the cartridge case dimensions:

The .458 SOCOM is rumored to be going through the SAAMI process, but it is not in SAAMI yet. That was 2 years ago that people began talking about that, so either SAAMI is just a slow process, or it isn’t happening.

We are trying to register both cartridges to the CIP, for the european market.
A proof barrel is needed so precise dimensional data about reamers and cartridges are also needed.
I can’t locate any tech sheet on the net, probably due to trade mark rights

I`m searching for the chamber dimensions of the .50 Beowulf. Is there a technical drawing with dimensions available?

Best regards and thanks in advance


A friend of mine registered the Beowulf to CIP as 12*7x42. The specs should be in the CIP website or Will Be published soon

Hi Pivi,

thanks a lot for answering.
At the moment there is no .50 Beowulf and no 12,7x42 listed at the CIP.
I hope, it will be published soon.

Best regards