I think you'd spend the rest of your life scraping a ram's horn thin enough to get it translucent. Probably the same for a Cape Buffalo's. Are they even hollow?
I'd go with a ox horn, or a buffalo. That would be a sharp (heh, heh) horn when done. The one's I've done (five, I think) have been plain old cow. My best effort is a 15" chocolate tipped F&I style that is carved to a octagonal tip and scrimshawed.
Learned a valuable lesson in trying to soften it for carving and fitting the end plug (which is held by wedging in the heated & soft horn and then tacking it in with thorns from a thorn apple tree). Boil it, but don't try and warm it in the microwave. It developed several blisters and a bubble that I ended up cutting out and having to fit a horn patch piece in its place. The patch is carefully form fit and riveted in place with rivets cut from a penny. Added about 30 hours work for a 15 second zap. Who knew? I worked the rectangular patch into the design my etching "MADE Ye IVLY MCMXC" beside a whitetail buck (copied out of one of the Book of Buckskinning series on engraving). On the top it is etched "CHAs. PEARSALL HIS HORN". Between the microwaving (which gave it a yellow tint in some spots), the gunpowder paste rub to set the scrimshaw, and a dab of maple Minwax to the darker tip, and then a beeswax rubbing, it looks authentically old. The help of a few bugs when I had left it in a drawer that slides into our attic crawl space further "enhanced" the character of the poor thing. Luckily, it appears whatever chewing insect (or mice?) got to it they didn't like the darker inner layers of the horn, so they didn't actually hole the horn.
Holds a full pound of powder.