Thread: Do you always need to case trim?

I trim every third firing. After 3 shots, they've grown .005" to .010" and it seems to vary from one case to another.
I trim to a length midway between SAAMI max and min. It's ideal if you choose a length that's short enough you trim a bit off every case so they are all the same.

If you want to use the same brass in several guns then you should full length size them every time and keep the brass length within SAAMI range. You will also need to keep cartridge overall length within SAAMI spec and check you haven't seated the bullet into the lands for one of the rifles. This is more likely if you use a stubby round nose bullet loaded to max SAAMI COAL. Most factory chambers are set so you can't reach the lands with a spitzer or boat tail bullet at SAAMI max COAL (don't quote me on that its just my limited personal experience).