HK416 ADJUSTMENTS AND TOLERANCES

Bolt Headspace: Go - 1.8507, No Go - 1.859*

Firing Pin Protrusion: Go - .0354", No Go - .0433" C.

Bore Erosion Gauge: 5.59 mm (Barrel Caliber: 5.56 mm)

Extractor Claw Gauge: Go - 1.28 mm

Extractor Claw Gauge: No Go - 1.59 mm

Barrel Nut Torque: 110 Nm +-10Nm = 81+-7 ft.lbs

Muzzle Device Torque: 60Nm +-10 Nm = 44.254 ft.lbs

Castle Nut Torque: 60Nm +-10 Nm = 44.254 ft.lbs

Lower Receiver Extension Torque: 59Nm +-10Nm = 44 +-7 ft.lbs

Handguard Torque: 7Nm +-1Nm = 5 ft.lbs  

The locking screw for handguard has a defined breaking point to prevent damage to

the handguard. The locking screw for handguard breaks off at a torque of 14 Nm = 10.33 ft.lbs.

Geisssele SMR HK handguard torque = 10 ft.lbs

Grip Screw Torque: 3Nm = 2.21 ft-lb