Question: Which bolt-action, magazine-fed, repeating rifle is the Charlton Automatic Rifle a fully automatic conversion of?
Context: The AK-47, or AK as it is officially known (Russian: Автомат Калашникова , "Avtomat Kalashnikova ", 'Kalashnikov's Automatic Rifle' ), also known as the Kalashnikov, is a selective-fire (semi-automatic and fully automatic), gas-operated 7.62×39mm assault rifle, developed in the Soviet Union by Mikhail Kalashnikov.  It is the originating firearm of the Kalashnikov rifle (or "AK") family. The Rieder Automatic Rifle was a fully automatic Lee–Enfield SMLE rifle conversion of South African origin.  The Rieder device could be installed quickly with the use of simple tools.  A similar weapon of New Zealand origin was the Charlton Automatic Rifle. An automatic rifle is a type of self-loading rifle that is capable of fully automatic fire.  Automatic rifles are distinguished from semi-automatic rifles in their ability to fire more than one shot in succession once the trigger is pulled.  Many automatic rifles are select-fire weapons which are capable of firing in fully automatic, semi-automatic or burst-fire modes.  Most automatic rifles are further subcategorized as battle rifles or assault rifles. The Charlton Automatic Rifle was a fully automatic conversion of the Lee–Enfield rifle, designed by New Zealander Philip Charlton in 1941 to act as a substitute for the Bren and Lewis gun light machine guns which were in chronically short supply at the time. The Howell Automatic Rifle an automatic conversion for the Lee–Enfield rifle.  The weapon was reliable but unergonomic for the user as the force of the recoiling bolt interfered with handling.  Similar conversions were the South African Rieder and Charlton of Australian/New Zealand origin which had full automatic capability. The Lee–Enfield is a bolt-action, magazine-fed, repeating rifle that was the main firearm used by the military forces of the British Empire and Commonwealth during the first half of the 20th century.  It was the British Army's standard rifle from its official adoption in 1895 until 1957.  .  It is often referred to as the "SMLE," which is short for the common "Short Magazine Lee-Enfield" variant. Christopher Miner Spencer (June 20, 1833 – January 14, 1922) was an American inventor, from Manchester, Connecticut, who invented the Spencer repeating rifle, one of the earliest models of lever-action rifle, a steam powered "horseless carriage", and several other inventions.  He developed the first fully automatic turret lathe, which in its small- to medium-sized form is also known as a screw machine. The Winchester Hotchkiss was a bolt-action repeating rifle patented by Benjamin B. Hotchkiss in 1876 and produced by the Winchester Repeating Arms Company and Springfield Armory from 1878.  The Hotchkiss like most early bolt-actions had a single rear locking lug integral with the bolt handle, but was unique in feeding multiple rounds from a tubular buttstock magazine similar to the Spencer rifle.  The .45-70 Hotchkiss was acquired in limited numbers by the US Navy as the M1879, and (in a slightly modified version) by the US Army and several state militias as the M1883, making it the first center-fire bolt-action repeater to be adopted by any major military (the distinction of first bolt-action repeating rifle to be a issued in great numbers as a standard military arm was the Swiss Vetterli 1869, which utilized very large rim-fire metallic cartridges). A repeating rifle is a single-barreled rifle containing multiple rounds of ammunition which are loaded into the gun's chamber from a magazine by means of either a manual or automatic mechanism, and the act of loading the rifle typically also recocks the firing action.  In common usage, the term "repeating rifle" is most often applied specifically to weapons in which the next cartridge is loaded by a manual action, as opposed to self-loading rifles, in which the recoil of one shot is used to cycle the action and load the next round. A machine gun is a fully automatic mounted or portable firearm designed to fire bullets in quick succession from an ammunition belt or magazine, typically at a rate of 300 to 1800 rounds per minute.  Not all fully automatic firearms are machine guns.  Submachine guns, rifles, assault rifles, shotguns, pistols or cannons may be capable of fully automatic fire, but are not designed for sustained fire.  As a class of military rapid-fire guns, machine guns are fully automatic weapons designed to be used as support weapons and generally used when attached to a mount or fired from the ground on a bipod or tripod.  Many (but not all) machine guns also use belt feeding and open bolt operation, features not normally found on rifles.
Answer: Lee–Enfield