# 23 - Charging handle latch roll pin
# 24 - Charging handle latch
# 25 - Charging handle latch spring
# 26 - Charging handle
# 27 - Firing pin
# 28 - Bolt carrier key screw, each (2 required)
# 29 - Bolt carrier key
# 30 - Firing pin retaining pin
# 31 - Cam pin
# 32 - Bolt carrier, Semi-auto
# 33 - Bolt gas ring, improved, each (3 required)
# 34 - Bolt
# 35 - Extractor spring
# 36 - Extractor spring insert
# 37 - Extractor
# 38 - Extractor pin
# 39 - Ejector roll pin
# 40 - Ejector spring
# 41 - Ejector
# 42 - Forward Assist Assembly
# 43 - Pawl spring pin
# 44 - Pawl spring
# 45 - Pawl detent
# 46 - Forward assist pawl
# 47 - Forward assist spring
# 48 - Ejection port cover
# 49 - Ejection port cover spring
# 50 - Ejection port cover pin
# 51 - Pin retaining ring
# 52 - Upper Reciever
# 53 - Rear sight elevation spring pin
# 54 - Forward assist spring pin
# 55 - Rear sight elevation spring
# 56 - Rear sight elevation knob
# 57 - Rear sight elevation index
# 58 - Index screw
# 59 - Rear sight assembly
# 60 - Ball bearing
# 61 - Elevation index spring
# 62 - Rear sight windage knob
# 63 - Rear sight windage knob pin
# 64 - Rear sight index spring
# 65 - Rear sight ball bearing
# 66 - Rear sight flat spring
# 67 - Rear sight aperture
# 68 - Rear sight ball bearing
# 69 - Rear sight helical spring
# 70 - Rear sight base
# 71 - Rear sight windage screw