Bolt Head

Heckler & Koch HK 51 - Design Details
... The two-piece bolt assembly consists of a breech (bolt head) and bolt carrier ... The bolt is held in battery by two sliding cylindrical rollers that engage locking recesses in the barrel extension (popularly called a "trunnion" BATF calls this a "moun ... camming surfaces driven by the rearward pressure of the expanding gases upon the bolt head ...

Savage Model 110 - Design
... The bolt is an easily-manufactured assembly, consisting of a tube with a rotating forward baffle and the bolt head (with locking lugs) at one end, a removable handle ... The receiver and bolt designs make the rifle relatively simple to produce with a left-handed bolt ... The bolt head of the Model 110 is a "floating" design A flat spring located behind the front baffle and bolt head assembly gives the assembly a small amount of free movement lateral to the bore axis ...

Rotating Bolt
... Rotating bolt is a method of locking used in firearms ... Johann Nicolaus von Dreyse developed first rotating bolt the "Dreyse needle gun" in 1836 ... The Dreyse locked using the bolt handle rather than lugs on the bolt head like Mauser M 98 or M16 ...

CETME Ameli - Design Details - Operating Mechanism
... roller-locked short recoil operating principle (where the barrel and bolt recoil together a short distance before they unlock), the Ameli uses the delayed blowback method of operation with a fixed barrel ... The heart of the operating system is the bolt assembly, which consists of a bolt head, locking piece and two cylindrical rollers, which upon ... in the barrel extension and the locking piece ensure that once a shot is fired, the bolt head absorbs the recoil impulse from the ignited cartridge through the base of the empty casing and transmits this ...

Winchester Model 70 - 1964 Through 1991 Model 70 - Post '64 Model 70 Action (Push Feed)
... rifles manufactured from 1964 to 1992 differed from early Model 70s in the following ways The bolt was changed significantly ... The bolt face was enclosed so that it fully surrounded the cartridge rim, in a similar way to the Remington 700 bolt ... While cheaper to manufacture than the undercut bolt face needed for controlled feed actions, it is also stronger, providing more support to the cartridge case head ...