Case capacity .308 Win vs Norma brass

[earplay]

Hi there,

Was wondering if anyone had experience changing from Win to Norma brass in .308. I roughly came up with about 1.2gns less capacity in the Norma using powder as a measure.

How does this translate to reduction in charge? I was running 45gns Varget behind a 178 Amax in the Win brass but have started working up from 43gns in the Norma. I also had my barrel shorted slightly so my velocity figures aren't a reliable guide.

Any rough ideas would be greatly appreciated!

Matt

 

[Code4]

I can't help but I'd be checking for consistancy. Pick the brand with the most uniform vol..

When changing components always work up again. There are no safe short cuts I'm afraid.

 

[Mikecr]

How did you compare capacity with Win to Norma?
Were both case brands fully fireformed to your chamber?

You'll have to work up a new load for a brass change.

 

[earplay]

I just used varget powder. Both cases at least once fired. I understand water would be a better gauge, just powder was quick and easy. I am in the process of working up a new load, was just wondering if anyone had made the same change.

With one of my 30-30 loads, a case capacity difference of 0.5gn worked out to require a 0.3gn change in charge weight.

Matt