300winchester brass versus Norma ( case capacity difference)

[magedon44]

Guys I'm currently shooting Winchester 300 win mag brass . I'm pushing the 190 bergers@ 3060 ft/sec with 81.5 g of Retumbo .

I can't find anymore Winchester brass for sale so I'm going to have to switch to Norma.

My question is - will these two manufactures have the same case capacity or will I have to add or back off on the charge amount in the Norma brass to hit 3060ft/sec to match my huskemaw turret?

Just seeing if anyone has any experience with these two brands.

Thanks!

 

[kbaerg]

If I remember reading on this site someplace correctly you will use less powder with norma brass. BUT for safety sake start low and work up powder charges to see if you can match your old load while watching for pressure signs. Never assume you can duplicate a load in different brass, the results could be bad.

 

[MagnumManiac]

I can tell you with absolute certainty that Winchester cases have LESS capacity than Norma cases, the same loads will produce LESS pressure and velocity in Norma brass.

Cheers.
gun)

 

[Greyfox]

I compared the new 300WM Winchester brass to new Norma brass, both sized to the same length.
Using a sample of 5 rounds of each I found that the Winchester brass holds 2.3grs less water than the Norma brass. Winchester-90.2grs; Norma-92.5grs. The empty case weight is Winchester-236 Norma 219. The variation in weight of the Winchester was 4gr, Norma 1gr. Neck wall thickness is the same at .014". The Norma brass has very tight primer pockets, looks perfect, and is slightly larger in dimensions when placed in my Wilson case trimmer. The Winchester, as usual has some dented necks and the brass finish is mottled. I could not size the new Winchester brass in the Wilson dye holder because of the smaller case dimension of the new brass. Fired brass fits OK. I get 10 reloads out of the Norma brass annealing after 5 or 6 loads, same for the Winchester brass.

 

[kbaerg]

Then I remembered wrong. (See what heat does to a guy during haying season)

 

[FEENIX]

Then I remembered opposite. (See what heat does to a guy during haying season)

Me too!