When I first saw a walking stick with a nicely formed buffalo horn handle a few years ago I was very curious as to how something as stiff as a buffalo horn tip could be bent into such a tight curve such as that seen in a stick. I have put this page on my web site so that anybody such as myself a few years ago can see the basics to bending horn.
Before horn can be bent it needs to be heated sufficiently to make it more supple, this usually means boiling for about half an hour prior to putting in the bending jig. Some stickmakers claim to be able to heat the horn to a sufficient temperature with just a hot air gun but I have not been able to achieve good results with this method.

Horn bending equipment ready for use once the horn has been boiled for about half an hour.

The pieces cut off the horn allow it to bend more easily against the former.

The buffalo horn set up in the bending jig after boiling. Heating up the former on the jig with a hot air gun also helps.

After further heating with a hot air gun the horn can be eased around the former with the help of a metal tube for leverage, shaped hardwood blocks and clamps.

The horn is worked around the former a bit at a time with clamps and the hardwood blocks, heating as necessary to maintain flexibility in the horn.

Once the horn has been completely bent tightly around the former it is allowed to cool down fully and "set" overnight.

The cool horn as it looks after removing from the jig, this sometimes requires a crow bar and wedges carefully used.

The end of the horn is cut roughly to length and re-heated with the hot air gun to make it more plyable. A clamp is then used to pull the horn into the desired shape.

This is the rough shape that is required for the handle and is now ready for final shaping.

I use a plastic template to check that I have got the right shape prior to final shaping with rasps, files and sand paper.

The handle has now been fitted with a piece of 10mm studding and a white horn spacer. Final shaping can now take place with rasps, files and sand paper. The handle is attached to the shank before final shaping to ensure a perfect joint. All that's needed then is lots of elbow grease and time to polish the handle to a great shine. UPDATE: I now form a dowel on the end of the shank to attach the handle and not studding any more because there is less chance of the stick breaking & also the stick feels better in use.
I hope you have found this page of interest. There are lots of stickmakers with loads more experience than me that do things in a similar way but everybody seems to have their own little ways of doing the same job based on experience.