...230 grain bullets at 3200fps. Brass is seasonal but if you are patient it can be had...
What kind of powder and charge are you using?
I've got a 30-378 Improved (holds 135 grains of water) and am fireforming still. However, I loaded up 5 fireformed cases with 101, 101.5, 102, 102.5, 103 grains of Retumbo and seated the bullets into the lands. I got the 230 grain Berger to 3150 fps with 103 grains of Retumbo, but the bolt was sticky. This danged Norma brass is so soft it's aggravating.