308 brass

[Snuby642]

So we have fc gmm and mag tec Brazilian brass first fired brass.

Case capacity is going to be different.
Should I take the percentage of less capacity into account for first load development?

I know the mag tec is thicker in the base. I will measure capacity with my powder tomorrow against the gmm.

Is this a proper way to start?
Have not loaded 308 yet.

300blk and 223 were jacking with me in small amounts , finally got a handle on that.

 

[lightman]

I don't think it matters if you start low and work up a load. If you change brass you should drop back a little on the charge and work up again. I've found using alcohol to measure case capacity is more accurate than either water or powder. Something to do with surface tension of the liquids. This may sound a little anal but if you're measuring things like this you may as well be accurate.

 

[Snuby642]

Ok wiskey or burbon? Lol

Was going to use powder but you're right.

 

[918v]

There are two kinds of CBC 308: 185gr mil spec and 180gr commercial. The commercial variant does not have a primer crimp. The capacity of the commercial is a little less than FGMM but close. The heavy mil spec stuff definitely needs a powder charge reduction.