Editing Breechblock (section)

=== Rotating bolt ===
Usually referred to as a bolt rather than a breechblock, a [[rotating bolt]] is perhaps the most common variant. It is so called, because its operation is similar to a pad bolt or barrel bolt. The bolt slides in the [[Receiver (firearms)|receiver]] along the axis of the barrel and is rotated in the same axis to lock or unlock it against a closed breech. It is the basis for the [[bolt action]], in which the bolt is rotated and retracted by a handle attached to the bolt. In some designs, the handle (sometimes called a [[cocking handle]]) rotates to lock against a shoulder in the receiver or body of the firearm. This type of locking is usually reserved for low-pressure applications such as the .22 cal [[Rimfire ammunition|rimfire]] series. More often, the bolt locks closed with two or more lugs that operate like a [[bayonet mount]]. Multiple lugs permit a smaller degree of rotation to lock and unlock the breech. Most types are front-locking and have the lugs mounted near the breech face. A notable exception is the rear-locking system used in the [[Lee–Enfield]].

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File:Bayonet-mount-01.svg|A rotating bolts locks in a way similar to a bayonet mount, such as shown here (but with much stronger lugs and locking grooves than shown).
File:Rotating Bolt.png|Operation of a rotating bolt
File:ТОЗ-17 разобр.JPG|A [[TOZ-17]] [[cadet rifle]] chambered for [[.22 long rifle]] which has been disassembled. The bolt is locked by the bolt handle being dropped into a notch in the receiver.
File:MauserSystem98Verschluss-03.jpg|A [[Mauser 98]] bolt showing two locking lugs just behind the face of the [[Bolt (firearms)|bolt]]. There is a third "emergency" lug in front of the bolt handle, in case the primary ones fail under pressure. In some designs the bolt handle itself may serve as the emergency "lug".
File:Rugersrcarrier.jpg|[[AR-15]] bolt carriers showing multiple locking lugs on the bolts
File:AR-15 NIckel boron bolt.jpg|An AR-15 bolt stripped from the bolt carrier
File:SMLEAction.jpg|A [[Lee-Enfield]] Mk III rifle with the bolt pulled back. The bolt lugs lock into the receiver bridge and are rear-locking.<ref>[https://www.youtube.com/watch?v=6e-H4XFOG78 How a Lee Enfield works], accessed 8 July 2021.</ref>
File:Winchester Model 1300 bolt and breech.jpg|Rotating breechblock and breech face of the [[Winchester Model 1200]] pump action shotgun.<ref>[https://www.youtube.com/watch?v=D5dazbwDOuM Winchester 1200 Firing Pin removal], accessed 6 July 2021.</ref>
File:Browning BLR.jpg|The [[Browning BLR]] lever action uses a rotating bolt.<ref>[https://www.youtube.com/watch?v=lHLDzCFrjm0 Browning BLR Review and Accuracy Report], accessed 8 July 2021.</ref>
File:Desert Eagle beside a box of Speer 325 Grain HP.jpg|The [[Desert Eagle]] is a gas-operated, semi-automatic pistol using a rotating bolt.<ref>[https://www.youtube.com/watch?v=yct-fd7FUEE 3D Animation: How a Desert Eagle works], accessed 8 July 2021.</ref>
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Rotating bolts can be adapted to [[Automatic firearm|automatic]] or [[Semi-automatic firearm|semi-automatic]] designs and [[Lever action|lever]] or [[pump action]]s. In these cases, the bolt is held by a bolt carrier. With the breech locked, an initial rearward movement of the bolt carrier causes the bolt to rotate and unlock. Similarly, when closing the breech, the final forward movement of the carrier causes the bolt to rotate and lock the breech. This action is commonly achieved by a slot cut in the carrier that engages a pin through the bolt perpendicular to the axis of the barrel. It is a type of linear cam.

[[Bolt action#Straight pull|Straight-pull bolt-action]] firearms do not require the operator to rotate the cocking handle to cycle the action. Some straight-pull designs may use a rotating bolt but other breech-locking mechanisms can be employed.