Luger 9mm hercules knob

Simple grip without fancy shapes at the top. What makes this model stand out is the space intended for a 9mm Luger bullet casing.
An additional advantage is separating the knob from the handle. A different printing material can be used, which not only improves the appearance but also provides a more secure grip.
If you check example photos you can observe black material outside. It's my favorite printing filament from Noctuo. It's called Noctuo Grip - soft touch, flexible like TPU but with much better grip. Easy to print (both together and separately)

3mf file contains bullet case mock for better visualization. You can print it along with this if you don't have the real ones...