Askins used IMR3031- which Waters felt might be too fast a powder so he used IMR4320 to get 2,400fps, while others use H4895 or IMR 4895. Seems to me, Whooters used IMR4320 as well. I personally think that round might properly support BLC2 or H335 in ball powders for lower pressure at that speed, but have no experience loading the .416 Myself. It is what I would build, if I was going to have a .416. As-is, I kinda like my 9.3's and .375's as my modern big bores.

The .416 Taylor was loaded to 2,400fps/400gr. (.032" and .049") Colorado Custom pure copper jacketed bullets by Charles Askins 50 or 60 years ago, Ken Waters about 45years ago in "pet Lods" with probably the only Ruger Ever factory chambered in that round, by John Whooters about 50 years ago in acustom rifle he took to Africa and shot 1 or more Cape Buffalo with it - WOW! time is rushing by nowadays.

Today, some people seem to download it a bit, other's not so much.