Happened upon a stash of new old stock 30 Rem ammo, now obsolete, and have been mulling over the pros/cons of trying to fire it in a 32 Rem rifle for the purpose of fire-forming 32 Rem brass for reloading, as 32 Rem is even more obsolete (if that is a real thing?). The physical characteristics of the 2 rounds are quite similar, and I have already determined that a 30 Rem round will chamber and extract smoothly in my 32 Rem rifle.
Now, I am not new to reloading, so I am aware that proper fit to the throat of the chamber and neck expansion of the brass are crucial to a good seal upon firing. Will the brass handle the roughly .013" expansion of the neck/shoulder to prevent blow-back pressure to the bolt face? I am not concerned in the least about accuracy of the .308" bullet bouncing its way down a .321" barrel, I will be "wasting" (actually capturing and recycling) the bullets for the sole purpose of fire-forming the brass to the dimensions of my 32 Rem chamber.
So, would you fire the factory loads of 30 Rem in the 32 Rem chamber, or pull the bullets and expand the necks to reload with a 32-cal projectile first?