When I first went to Africa on a plains game hunt I had heard from many sources including my outfitter to use a 180 gr bullet.
I was planning on using my Rem 700 in 7mm RUM. It has a 9.5 twist barrel.
Wanting to use Barnes bullets, I called Barnes and spoke to their technical people and was told that with the 175 gr TSX FB bullet, it would be marginal if I would be able to stabilize it, especially shooting it at near seal level in Africa.
Well, I tried it working up a load using H1000. Sure enough, they were key-holing at 100 yards.
So, I dropped to the 160 gr TSX FB bullet and worked up a load using H1000. My rifle shot that bullet at 1/2 MOA and I was very pleased with it.
I had read and the technical people at Barnes told me at the time that their bullets would perform like and lead coarse bullet weighing 30% more. So essentially, the 169 gr Barnes TSX would perform like a 178 gr lead core bullet.
Long story short, that rifle took 13 plains game animals from Kudu, Gemsbok, Sable, Blue Wildebeest and Zebra all the way down to Warthog. Every one of those animals dropped where they were hit and I only recovered 1 bullet and that was from the off shoulder of my Blue Wildebeest after taking him squarely through both front shoulders.
Since that first trip I will only hunt with Barnes bullets for big game and I would highly recommend to the OP to use the 160 gr bullet in his 7mm.