2 barrel with receiver and gas system – SIG SAUER SIG556xi User Manual
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2.1.2 barrel with Receiver and gas system
The barrel is mechanically mated to the receiver. The flash suppressor is screwed onto the muzzle end of the barrel which
features a 0.5 x 28 TPi thread pattern. The gas block, which is fixed on the barrel, contains the gas port, locates the gas system
(gas tube and operating rod), accepts the front sight and also serves as support for the handguards. The receiver guides the
bolt and bolt carrier, and houses the locking system. an accessory mounting rail is fixed to the upper part of the receiver,
providing an attachment point for sighting systems and other accessories.
1 Accessory Rail
2 Bolt Cover
3 Charging Handle Catch
4 Gas Tube
5 Operating Rod
(inside gas tube
6 Front Sight Rail
7 Gas Valve
8 Takedown Pin Hole
9 Receiver
10 Bolt & Bolt Carrier (hidden)
11 Pivot Pin Hole
12 Barrel Nut
13 Barrel
14 Gas Block
15 Flash Suppressor
1
2 3
4
5 6 7
8 9
10 11 12
13 14
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