A shroud is provided for a firearm having a longitudinal barrel. The shroud is configured to co-operate with formations provided on the firearm barrel such as to provide axial alignment therebetween. The shroud further comprises means for mounting one or more devices to the shroud. The alignment between the barrel and the shroud provides for alignment between the device(s) and the barrel. A firearm comprising such a shroud, and a method of configuring a firearm comprising the shroud are also provided.