I am hardly a Buffalo hunting expert but have killed a Cape Buffalo with my DG rifle. It is a 375HH, is exceptionally accurate when fired from a bench or other solid rest and I am reasonably accurate with it off sticks. I can hit an 8" gong off sticks from 200y every shot and am very confident with it. I have taken, Blue Wildebeest, Kudu and the Buff with the 375 and it is a great all round cartridge for Africa.
Mine is an old custom rifle built by ER Shaw from Pennsylvania on an Enfield Pattern 14 magnum CRF action in a lovely figured walnut stock. It has an old supple leather sling that I use to carry it Rhodesian style (weak side muzzle down) as I am loath to use the African carry unless I am at the front of the column and as the client that is not the case. Rhodesian style if you practice it even a little can enable you to safely carry with comfort and can deploy onto the sticks in only a couple of seconds.
My scope is a 1-6x Kahles K16i with illuminated reticle in steel Leupold 30mm rings. The thermal expansion differences of aluminum vs steel means that if you use aluminum rings, sooner or later they will get loose. It may be years later depending on their use and abuse. For DG rifles, and benchrest competition rifles, I use steel rings on steel bases. If your aluminum rings stay tight, good for you. Most of mine do too. But, again if your life is on the line, you eliminate every variable you can and try to minimize the others. I do not use QD mounts for that same reason. They are handy until they become a liability. My primary DG rifle does not have iron sights but my secondary one does. With the scope at 1x and the red dot and ring illuminated, I can hunt with it just like a red-dot reflex sight with both eyes open and in low light conditions. Dialed to 6x it is clear enough to score tgts at 200y and shoot steel out to 400y. I have never used it to hunt game past 200y but it is capable out to 250 or 300y before running out of velocity (not accuracy). For Buffalo you want to be closer than 100y or even 80y if possible. They are tough and long shots are for gophers.
My rifle shoots all factory loads I have tried very well, and most are sub MOA. Reloads in PPU brass do not agree with it for some reason. So, those are avoided. My chosen load for Buff is Barnes 300g TSX and even though the factory claimed velocity is 2500fps, my rifle averages closer to 2600fps on the chrono which helps when the chips are down. One thing to consider. I think 375HH is adequate for Buffalo but it is not the ideal Mbogo stopper. If I ever hunt them again, I will be using something larger, like the 458WM or similar. Yes, they kick a little more but not enough to matter. If you can handle a light weight upland 12ga with high brass loads, you can handle a DG rifle.
375HH ER Shaw Custom
Buffalo Down
100y Groups - White tgt pasters are about 1/2" diam
