45 Auto

I have a 45 ACP with the following headstamp I, does anyone know who made this cartridge?
Thank You Carolyn

I think there have been previous posts on this. It stands for INDEPENDENCE BRAND ammo. Might originally have been Brazilian, I don’t recall all the info.


Their are three known variations to that headstamp:

I 45 AUTO {large size]
I 45 AUTO [small size]
I .45 AUTO

For whatever that is worth.