To: saleman
Primary headspacing is usually set as you describe - where the barrel and receiver join (at least for most 20th-century military rifles). There are oddballs, though - in tilting-bolt designs like the SKS and the FN-FAL, headspace is tweaked by adjusting the thickness of the bolt locking shoulder. The HK G3 (HK-91) and its small-bore relatives rely more on bolt-to-bolt carrier gap than headspace, due to the roller-locking design being adjustable with different diameter rollers.
17 posted on
04/29/2017 10:25:04 AM PDT by
Charles Martel
(Progressives are the crab grass in the lawn of life.)
To: Charles Martel
Primary headspacing is usually set as you describe - where the barrel and receiver join (at least for most 20th-century military rifles). There are oddballs, though - in tilting-bolt designs like the SKS and the FN-FAL, headspace is tweaked by adjusting the thickness of the bolt locking shoulder. The HK G3 (HK-91) and its small-bore relatives rely more on bolt-to-bolt carrier gap than headspace, due to the roller-locking design being adjustable with different diameter rollers. And as on the British Number 4 series Lee-Enfield rifles, that use interchangable front bolt faces in different graduated lengths to make the adjustment, used with the rimmed .303 British MkVII cartridge. Works like a charm, all you need is a headspace gauge and a selection of bolt heads.
44 posted on
05/02/2017 4:00:37 AM PDT by
archy
(Whatever doesn't kill you makes you stronger. Except bears, they'll kill you a little, and eat you.)
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