As stated, I have personally had excellent performance with the Swift A-Frame as a first shot on multiple cape buff. If you want to use a Nosler Partition for your first shot, be my guest. You pay your money and you take your chance. It is, after all, your safari and ultimately, your life that's on the line.
My suggestion is that you contact your PH and see what his recommendation is for the first shot. After all, it's his neck, too and he is a professional hunter, so it's not only his business to know, but his business to advise you accordingly. Should you bugger the shot or if your bullet fails and your buff heads into the jess after the first shot, it's his responsibility to dig it out. If he believes you are competent, he will invite you to accompany him on that mission. If not, he will have a tracker escort you back to the safari car while he goes in after it. I would be surprised if he recommends the Nosler Partition as a first shot on cape buff. Please let us know what he says on the matter and if you decide on a Nosler Partition for the first shot on your cape buff, be sure to let us know how it worked out for you.
Any bullet is capable of failing, given the right set of circumstances. When hunting DG, it is wise to stack the odds in your favor. I don't receive freebies from Swift or Nosler. Neither pays for my safaris. It makes no difference to me what bullet you use. But it should make a difference to you. Seek out the advice of professional hunters who hunt DG day in and day out. Go to the DSC and SCI conventions and speak to the professionals who populate the outfitter booths there. See what they recommend.
I have never tried a Barnes TSX on cape buff, so I have no opinion. North Forks don't feed reliably in my .416 Rigby, so I have never hunted with them. Woodleigh Weldcores are, IMO, also too soft for buff. Again based on personal experience, my opinion of the Federal TBBC is low. I am bringing Woodleigh cup point monometal solids with me on my next hunt, and I'll let you know how they do afterwards. My PH recommended them for both cape buff and elephant, which are on our menu.
Good hunting!
