Editing Thompson submachine gun (section)

==Features==
===Operating characteristics===
[[File:Thompson1928a1.jpg|thumb|Thompson M1928A1, field stripped]]
Early versions of the Thompson, the Model 1919, had a fairly high cyclic rate of fire, as high as 1,200&nbsp;rounds per minute (rpm), with most Model 1921s at 800&nbsp;rpm. This rate of fire, combined with a rather heavy trigger pull and a stock with an excessive drop, increases the tendency for the barrel to climb off target in automatic fire.<ref name="Dunlap, Roy F. 1948 p. 299"/><ref name="George, John 1981 p. 395">{{harvnb|George|1981|p=395}}</ref> In 1927, the U.S. Navy ordered 500 Thompsons but requested a lower rate of fire. Thompson requested that Payne develop a method of reducing the cyclic rate of fire. Payne then replaced the actuator with a heavier one, and replaced the recoil spring with a stiffer one; the changes reduced the rate of fire from 800 to the 600&nbsp;rpm of the U.S. Navy Model 1928. Later M1 and M1A1 Thompsons averaged also 600&nbsp;rpm.<ref name="Dunlap, Roy F. 1948 p. 299">{{harvnb|Dunlap|1948|p=299}}</ref> Compared to more modern submachine guns, the Thompson is quite heavy, weighing roughly the same as the contemporary [[M1 Garand]] semi-automatic rifle, and requires a lot of cleaning. This was one of the major complaints about the weapon by [[U.S. Army]] personnel to whom it was issued.<ref name="rt66.com"/>

[[File:Thompson 21 field stripped.jpg|thumb|left|Thompson 1921, field stripped]]

Although the drum magazine provided significant firepower, in military service it was found to be overly heavy and bulky, especially when slung on the shoulder while marching.<ref name="George, John 1981 p. 395"/> The M1928A1 Thompson drum magazine was rather fragile, and cartridges tended to rattle inside it, producing unwanted noise.{{sfn|Pegler|2010|p=26}} For these reasons, the 20-round and later 30-round box magazines soon proved most popular with military users of the M1928A1, and drum compatibility was not included in the design of the wartime M1 and M1A1 models. The Thompson was one of the earliest submachine guns to incorporate a double-column, staggered-feed box magazine design, which undoubtedly contributed to the gun's reputation for reliability. In addition, the gun performed better than most after exposure to rain, dirt, and mud.<ref name="rt66.com"/>

The selective-fire (semi or fully automatic) Thompson fires from the "open bolt" position, in which the bolt is held fully to rearward by the sear when cocked. When the trigger is depressed, the bolt is released, traveling forward to chamber and simultaneously fire the first and subsequent rounds until either the trigger is released or the ammunition is exhausted. This eliminates the risk of "[[Cooking off|cook-off]]", which can sometimes occur in closed-bolt automatic weapons.

===Disassembly===
The 1928 variant can be disassembled easily by first detaching the stock, then sliding off the lower receiver and then simply removing the internal parts, cleaning them, and then putting it back together. When opened up, the Thompson features a small number of parts that need to be removed including the spring, bolt, Blish Lock, and actuator bolt.