Editing FAMAS (section)

===Ammunition===
[[File:FAMAS.jpg|thumb|Cutaway of the muzzle of a FAMAS F1 on display at the Weapons Department in the Museum of Art and Industry in Saint-Étienne, France]]
[[File:Fusilier marin remise des fourragère le 06 juin 2009. Recadré.jpg|thumb|A fusilier marin with his FAMAS G2]]
The FAMAS uses a delayed blowback operating system that functions best with French-specified steel-casing 5.56×45mm ammunition. Using standard brass-casing [[5.56×45mm NATO]] ammunition employed by other armies can create over-pressure and case ruptures in the FAMAS during extraction, which can lead to severe malfunctions.<ref name="secretdefense.blogs.liberation.fr">{{Cite web |url=http://secretdefense.blogs.liberation.fr/defense/2009/09/larm%C3%A9e-a-de-s%C3%A9rieuses-difficult%C3%A9s-avec-les-munitions-du-fusil-famas.html |title=L'armée rencontre de sérieuses difficultés avec les munitions du fusil Famas |access-date=3 June 2019 |archive-url=https://web.archive.org/web/20150111004617/http://secretdefense.blogs.liberation.fr/defense/2009/09/larm%C3%A9e-a-de-s%C3%A9rieuses-difficult%C3%A9s-avec-les-munitions-du-fusil-famas.html |archive-date=11 January 2015 |url-status=live }}</ref> Using incorrectly built ammunition also results in approximately two minor injuries for every million rounds fired from a FAMAS.<ref name="secretdefense.blogs.liberation.fr"/> As a result, the French military has discreetly banned the use of foreign-produced ammunition in all French-issued FAMAS.<ref name="secretdefense.blogs.liberation.fr"/> However, fluting the chamber will completely remove these malfunctions, although the brass casings will still be deformed and will not be able to be reloaded without reshaping.

The FAMAS F1 uses a proprietary 25-round magazine. It has a chrome-lined barrel with 1 turn in 12 inch (1:12 inch) rifling and functions best with the {{convert|55|gr|g|abbr=on}} (M193 type) ammunition. When using the French made 5.56&nbsp;mm {{convert|55|gr|g|abbr=on}} ammo it has a muzzle velocity of {{convert|3150|ft/s|m/s|abbr=on}}.<ref name="HoggWeeks2000">{{cite book |title=Military Small Arms of the 20th Century |edition=7 |last1=Hogg |first1=Ian V. |last2=Weeks |first2=John S. |publisher=Krause Publications |year=2000 |pages=238–239 |isbn=978-0873418249}}</ref>

The FAMAS G2 uses M16-type, NATO-compatible 30-round [[STANAG magazine]]s.<ref name="HoggWeeks2000" /> It has a chrome-lined barrel with 1 turn in 9 inch (1:9 inch) rifling and functions equally well with both the older {{convert|55|gr|g|abbr=on}} (M193 type) ammo and the newer {{convert|62|gr|g|abbr=on}} (SS109 type) ammo.<ref name="HoggWeeks2000" /> When using the French made 5.56&nbsp;mm {{convert|62|gr|g|abbr=on}} ammo it has a muzzle velocity of {{convert|3035|ft/s|m/s|abbr=on}}.<ref name="HoggWeeks2000" />

During training with blank ammunition, a [[Blank-firing adapter|special plug]] is added to the muzzle of the FAMAS. This plug is necessary for automatic or semi-automatic blank fire operation, and functions by blocking part of the gas used in a blank cartridge.