Manual

SIG 556 Operators Manual 29 P/N 1511203 VER 12.7.2
4.1.1. Unlocking Of Bolt, Extraction, & Ejection
• The gas pressure, generated by the burning powder, drives
the bullet up the barrel (13).
• As soon as the projectile passes the gas port (15), propel
lant gas flows through the adjustable gas valve (14).
• The gas pressure acts on the operating rod (1) which push
es the bolt carrier (4) to the rear.
SIG556 OM 12.06.qxp 1/8/2007 2:25 PM Page 29