I use Peregrine BushMaster bullets for cape buffalo in 577 NE. They are outstanding. With a good shoulder shot on a cape buffalo they usually go right down where they are shot. Perfect and consistent terminal performance.
As far as I am concerned they are among the the best bullets on the market.
Regarding the expansion.
Expansion is consistent, as advertised. I have found another cool thing about the expansion. It is directly proportional to the velocity. In my .557NE I don't want much expansion, so my moderate MV of 1,850 fps gives me the exact expansion that I want, about .650 evenly all around the bullet. ( So, I call it a Semi Expanding bullet at this slow velocity.) Give it more speed, and you get more expansion, always consistent and even, all around the bullet.
I am booked for 6 cape buffalo next year and I will be using the same 700 grain, 577 NE Peregrine BushMaster bullet.
A good way to get Peregrine bullets is to order them ahead of time for your next trip to Africa and have them dropped at your guest house before you arrive.
Peregrine sevice is excellent.
Brian Gallup