The Khyber Rifles was and is an actual regiment.

King of the Khyber Rifles (January 15-17, 1982)

It was also the headquarters of the Khyber Rifles, and the collecting station for the Khyber tolls.

Dating from the late nineteenth century the regiment provided the title and setting for a widely read novel, King of the Khyber Rifles.

The headquarters of the Khyber Rifles was at Landi Kotal.

King of the Khyber Rifles (1919 novel)

"There's an outpost of the Khyber Rifles," he added, pointing to a distant mountain fortress for the famous Pakistani militia.

He turned the rude levies which formed the Khyber Rifles into a fine corps, ready to serve the Indian government wherever they might be required.

Khyber Rifles was in fact regularized during the 1965 war and fought with distinction in Kashmir.

It is forbidden for foreigners to travel on this road without an armed guard from the Khyber Rifles - you'll be assigned one after immigration.