I used 140 grain Nosler Ballistic Tip bullets in a 7 mm Rem mag on my first African hunt 20 years ago. The outfitter and guides said that was too light of a bullet, but my Kudu, Blue Wildebeest, and Gemsbok all went down with one shot. Then I shot a Waterbuck that we didn't find for 5 days and many man hours of looking later. When we finally found him he was running with his cows like he had never been shot. I then shot a second bullet in him and he fell dead. Inspecting my shots, my first bullet went through his chest and he had licked clean both of the bullet's entrance and exit holes. My second shot hit within 2" of my first and killed him.
On my subsequent African hunts with my 7mm RM I used 160 grain Accubond bullets.
