This cartridge was created by Ross Seyfried by modifying 577 Nitro cases. Besides from forming, the rim has to be turned down to fit the bolt face. Either standard belted magnum or 416 Rigby rim size is used as the bolt requires. Length allows chambering in magnum Mauser actions with minimal modifications. Modified magazine capacity is three cartridges. Seyfried reports very satisfactory accuracy, no doubt a result of careful chambering and quality workmanship throughout the rifle and load. Nyati (n-ya-te) means Cape buffalo in several African languages and this is certainly a good name for a cartridge delivering so much bullet and energy. The 585 give those who really want power a much more affordable option, compared to the big British double rifles which can often demand tens of thousands of dollars. However, one must mention recoil. It is an open question as to how many among us can tolerate the kind of recoil this cartridge will generate with full power loads. In a 10 pound rifle with a good muzzlebreak, top loads will generate a mere 20 foot pound. Perhaps a better understanding of what this means is this: Imagine having this 10 pound rifle dropped off a 32 foot cliff and catching it with your shoulder. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.