This development named the Pattern 1913 Enfield or P13, included a front locking, dual lug bolt action with Mauser type claw extractor as well as a new, powerful rimless .276 Enfield cartridge. The design carried over a Lee–Enfield type safety at the rear of the action and a bolt that cocked on closing to ease unlocking of the bolt during rapid fire. An advanced design, for the era, of aperture rear sight and a long sight radius were incorporated to maximize accuracy potential. Ease of manufacture was also an important criterion. However, the onset of World War I came too quickly for the UK to put it into production before the new cartridge could be perfected, as it suffered from overheating in rapid fire and bore fouling.