bolt face

bolt face

[′bōlt ‚fās]
(ordnance)
That portion of a gun bolt that abuts the base of the cartridge case.
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References in periodicals archive ?
The thrust bushing goes between the reamer and the bolt face.
Still, short stroking can produce a double feed because the bottom of the bolt face, by dragging on the rim of the top cartridge in the magazine box, can push it forward.
The bigger bolt face and lengthier receiver means there's a whopping chunk of reciprocating mass being fueled by a correspondingly whopping dose of propellant gases.
The bolt face is recessed and the hook-type extractor takes a goodly-sized bite of the case rim.
So unlike a Remington, if headspace is slightly altered by modifying the receiver face, bolt face or lapping the locking lugs, we won't need a chambering reamer to bring it back to spec.
The bolt face has three lugs, allowing for a 70-degree bolt throw, as well as a fully machined bolt.
What set the Gew 98 apart from it's predecessors included a third safety lug, located just ahead of the bolt handle, which locked in the open bolt way beneath the receiver bridge, a shrouded bolt face and a guide rib that contributed to the smooth cycling of the straight handled bolt.
Insert firing pin protrusion gage in barrel until bottom end of gage seats firmly against bolt face
The bolt's operating cam then forces the bolt face to pivot downward, aligning a cartridge feed groove in the left side of the bolt with the chamber.
One quandary with making a bolt gun feed from a detachable magazine is getting the bottom edge of the bolt face low enough (or the top edge of the round to be fed high enough) that the bolt can push it to the chamber.
The bottom of the bolt face is relieved to allow the case head to slide smoothly up the bolt face with its rim beneath the extractor hook.
It's OK to use CLP to clean the barrel, the chamber, the rest of the op rod, and the bolt face, but wipe them dry before firing.