WHAT DOES 17 HORNET BRASS MEAN?

I have a Savage seventeen Hornet. It is an extremely successful very little cartridge. I like it but for me a 20 Realistic within an AR has all but replaced it.Years back, an acquaintance who labored at Remington informed me that much more Model 700 rifles in .17 Rem. have been delivered to Australian fox hunters than to dealers in The us as it did