The barrel of a power actuated tool for driving a fastener into a substrate upon detonation of an explosive charge, comprises front (4) and rear (2) barrel sections mounted for telescopic movement to absorb recoil upon firing. The sections are held in assembled relation by a retainer element (14) and are such that assembly and disassembly can occur by manipulation of one barrel section relative to other without the need to remove the retainer element (14).
