As the replacement for the SMLE Mark III, the Lee-Enfield Rifle, No. 4 was first issued in 1939 but not officially adopted by the UK until 1941. The No. 4 action was mostly similar to its Lee-Enfield family predecessors but lighter, stronger, and most importantly, easier to mass produce. Unlike the SMLE, the No 4 Lee-Enfield barrel protruded from the end of the forestock. The No. 4 rifle was considerably heavier than the No. 1 Mk. III, largely due to its heavier barrel and the new bayonet which was designed to go with the rifle. About four million of the No. 4’s were made in Britain, the USA, Canada, India and Australia.