Thread: Fire forming 270 to 280ai

Ahhhhhhhh, yeah maybe. I'd be a bit more cautious than what your method lays out but your general process is right.

I'd be getting the water capacity of the .270 and the .280AI and working out the percentage difference in terms of capacity. Then confirming the start load of RL22 in the .270 isn't under the safe start load for the .280 and double checking it!

What you have with fireforming like that is a known excessive headspace condition and you are intentionally shooting it... How you work around it is by 'correcting' the headspace to secure the case head against the bolt face - either by creating a false shoulder by necking up and back down or jamming the pill into the lands and shooting it that way. Jamming the pill into the lands is the option that gives the steepest pressure curve hence a bit of caution in making sure the load is what you think it is... Against that, blowing the case shoulder out does absorb some energy though its theoretical mostly.