I recently acquired what I thought was a Savage .250 bolt gun. So I got all items needed to reload a Savage .250 cartridge. It came with a box of ammo. Mounted A scope did my first shots, anyway since I was going to reload I found that the cases was forming a more prominent neck. Which I’m thinking possibly its a AI fireform brass now. Checked barrel it’s confirme this is a .250 AI. What load development should I start with? Try to check for .250 AI all I find is .250/300 loads are the same?