beginning of case head separation?

[scottishkat]

Bob4

The data on the web is newer than the number 4. After review the brass cases used in the number 4 were Winchester the primers were 215M. The new data on the web is with Remington brass and Remington 9.5M primers. That's probably all the difference it takes. The win cases and nosler are about the same weight 215gr I am betting the rem brass was probably 230gr or heavier.

I am not certain if Barnes is shooting for their data I think most are doing it by software now I still like Noslers data. The heavier the case the higher the pressure.

If you visit the Norma web site you can see the difference created by light and heavy brass in the 300 win mag.

As nvreloader states the most accurate method of measuring case capacity is the weight of water it can hold as I am sure some brass alloy can be heavier than others.

Sorting brass by weight is less accurate but it also works.

Good luck and shoot straight

Bob

 

[bob4]

Thanks to everyone that discussed this with me. Much appreciated. Last I was out I found that 67. g gave me under moa. Plenty middle of the road and no issues with pressure.So I'll tweak the seating depth and keep that load on paper for a back up if other supplies run short. I need to learn more about temp sensitive powders. I'm in Florida and it gets **** warm here in the summer and this isn't where I hunt.