https://palmettostatearmory.com/psa-pa-15-16-m4-phosphate-5-56-nato-1-7-classic-rifle-olive-drab-green.html
PRODUCT DETAILS
DETAILS
Caliber: 5.56 NATO
Barrel Length: 16 inches
Barrel Profile: M4
Barrel Steel: Chrome Moly Vanadium
Barrel Finish: Phosphate
Chrome Lining: No
Muzzle Thread Pattern: 1/2" x 28
Twist Rate: 1 in 7"
Barrel Extension: M4
Gas System Length: Carbine
Diameter at Gas Block: .750"
Gas Block Type: F-marked Front Sight Base
Muzzle Device: A2 -style
Receiver Material: Forged 7075-T6
Receiver Type: M4
Handguard Type: M4 with heat shields
Bolt Material: Carpenter 158 Steel
Bolt Carrier Profile: Full Auto
Fire Control Group: Standard Mil-Spec Trigger Group
Grip: A2-style, ODG
Stock: M4-style, ODG
Buffer Tube Length: Carbine
Buffer Tube Diameter: Mil-spec
Overall Length: 32 inches
Weight (as configured): 6.8 lbs