What is this?

[Daan Kemp]

That is the volley sight, intended for extremely long range volley shooting. You are lucky to have a complete set of volley sights, the one on the fore end as well as the one on the action at the back. The front sight fits in the indent at 22 on the dial.

Most of the early WWI Lee Enfield No1 and P14 rifles had volley sights, that were discontinued when trench warfare made them obsolete. Most of the rifles fitted with volley sights only have the dial on the fore end left.

Volley shooting. The whole company or battalion assemble, set the volley sights to the required distance, and fire the number of rounds determined. At the receiving end they will be wondering where this sudden hailstorm or lead is coming from. Usually at a forming up place before an attack, logistic concentrations, etc. Disrupting activities with no prior warning.