90gr olde eynsford is my 200 yard load in my 58cal hawken. More than plenty, especially with sabots and conicals.
It appears a 54 or even a 58 PRB would have less than 500FPE left after 100 yards with a 90gr load.
http://www.namlhunt.com/traditionalmldata2.htmlhttp://www.namlhunt.com/traditionalmldata3.htmlThat sure would not be my choice for elk. I guess my definition of "more than plenty" is vastly different than yours.