Home Forums Hunting & Shooting Long Range Hunting 300 Norma Magnum case dimensions

I am looking for info on the relatively new non-belted 300 Norma, not the older belted 308 Norma Mag. I wonder if any of you could provide me with case dimension info as well as some load data. I heard it is based off of the 416 Rigby case but is about 2.5" long. What is the actual diameter of the rim, head and shoulder? What is the length from the base of the case to the shoulder? What is the shoulder angle? How long is the case and how long is the neck? How does the case capacity compare with the 300 Win Mag or 300 Weatherby? Where can brass be purchased?

I am considering setting my 300 Win Mag barrel back and rechambering to the 300 Norma. The action is a Win 70 Classic Stainless with pre-64 type action. Would this modification be safe? Thanks for any info you can provide, Rufous.

It's just the 338 version necked down. Here's the info on the 338

http://en.wikipedia.org/wiki/.338_Norma_Magnum

good link i will send you a case if you like

just PM

its awesome!

One issue with the .585 diameter cartridges has to do with the thickness of the barrel between the threads and the chamber. Many 416 Rigby's have been built on M70's and 98 type Mausers. However the Rigby is loaded to very moderate pressure. Loaded to high pressure and it is possible to expand the barrel shank into the action threads and perhaps damage the action. The RUM's are on the very edge of acceptable.