300 Norma Mag data?

[Torchy]

Hey guys I am having a hard time finding a case diagram of 300nm brass. Is there a saami spec?

Couldn’t find it on saami’s website.
Seems like data for this cartridge is all over the place.

Trying to trim brass and don’t know what to trim to.

 

[Laseredge]

https://en.m.wikipedia.org/wiki/.300_Norma_Magnum

2.492” is what I use.

 

[Torchy]

https://en.m.wikipedia.org/wiki/.300_Norma_Magnum

2.492” is what I use.

Thanks for the help. I saw that too but wasn’t sure if it was accurate. That same data from wiki states a COL of 146 thou longer than what Norma says their COL is. But Norma themselves don’t publish a case dimension at least that I could find.

 

[Supersubes]

The three reamer prints I have all call out the the chamber length as 2.502.

 

[Torchy]

The three reamer prints I have all call out the the chamber length as 2.502.

Welp awesome. I’m going to roll with y’alls info.

After sizing all my new Peterson brass and not bumping my shoulders at all, they are all measuring 2.482-2.486 before any trimming at all. Think I’ll be fine?

 

[Supersubes]

I’d trim them so there is .010-.020 clearance.

 

[christopher.dow]

http://www.cip-bobp.org/homologation/uploads/tdcc/tab-i/300-norma-mag-en.pdf

1” = 25.4 mm