Editing AK-74 (section)

===Barrel===
[[File:Internal Troops of the Ministry for Internal Affairs (Russia) (494-28).jpg|thumb|left|An AK-74M muzzle device venting propellant gases]]

The rifle received a new barrel with a [[Chrome plating|chrome-lined]] bore and 4 right-hand grooves at a 200&nbsp;mm (1:7.87 in) or 37 calibers [[Rifling#Twist rate|rifling twist rate]]. The front sight base and gas block were redesigned. The gas block contains a gas channel that is installed at a 90° angle in relation to the bore axis to reduce bullet shear at the port hole. A pair of support brackets are cast into the gas block assembly and are used to attach a BG-15c or [[GP-25]] [[Underslung grenade launcher|underslung]] [[40 mm]] [[grenade launcher]]. Like the AK-47 and AKM, the muzzle is threaded for the installation of various muzzle devices such as the standard [[muzzle brake]] or a [[blank-firing adaptor]], while a spring-loaded detent pin held in the front sight post prevents them from unscrewing while firing. However the muzzle threads have been relocated to the front sight base for both easier and more economic replacement in case of thread damage. The distinctive standard-issue muzzle brake features a large expansion chamber, two symmetrical vertical cuts at the forward end of the brake and three non symmetrical positioned vent holes to counteract [[muzzle climb|muzzle rise and climb]] as well as lateral shift to the right much like the AKM's offset muzzle brake. A flat plate near the end of the brake produces a forward thrust when emerging exhaust gases strike its surface, greatly reducing recoil. The muzzle brake prevents backblast from reaching the firer, although it is reported to be harsh on bystanders as the muzzle gases are dispersed to the sides.<ref name="hogg">{{cite book |first1=Ian |last1=Hogg |first2=John |last2=Weeks |name-list-style=amp |date=2000 |title=Military Small Arms of the 20th Century |edition=7th |location=Iola, Wisconsin |publisher=Krause Publications |isbn=0-87341-824-7}}</ref> The standard-issue AK-74 muzzle brake has been subtly revised several times since the 1970s.<ref>{{cite web |url=https://www.k-var.com/compensator-us-made-for-ak-74-545x39-and-556x45-calibers-24x15mm-right-hand-threads |title=AK-74 Muzzle Brakes/Compensators |website=K-VAR Corp. |access-date=16 November 2014 |archive-url=https://web.archive.org/web/20190110073911/https://www.k-var.com/compensator-us-made-for-ak-74-545x39-and-556x45-calibers-24x15mm-right-hand-threads |archive-date=10 January 2019 |url-status=dead}}</ref>