Wheeler Engineering compact gunsmithing kit 26-piece

Wheeler Engineering 26 Piece Compact Rifle Set - Wheeler's Space-Saver Screwdriver, which includes 26 of the most commonly used bits:

10 standard
10 Allen keys
3 cross
3 star (Torx)

A quality and correctly selected bit means an end to damaged screw heads on any weapon you work with.

The set also includes

conversion bit from hexagon to tetrahedron (allows you to use e.g. 1/4'' nuts)
6cm long #2 cross bit, perfect for installing a gun boot
magnetic screwdriver with a hollow handle, suitable for storing additional bits