Major Options – Length, twist, caliber, chrome lined, profile, chamber, material, quality/testing, gas tube, Front Sight, Gas block
Rifling twist options – 1:7, 1:9, 1:12
Costs $200-$600
Tier One – High Pressure Testing (HPT), Magnetic Particle Inspection (MPI)
Tier Two – Chrome Lining – not true 5.56 chambers
Other Parts Required: Gas tube, gas block, front sight assembly, Delta ring assembly, handguards / rail assembly, muzzle device, bayonet lug
Things to consider about AR-15 Barrels
Barrel Length
Standard length for the AR15 barrel are; 7″, 10″, 10.5″, 11.5″, 14.5″, 16″, 18″, 20″ and 24″. Most common are 16″ and 20″. NFA rules apply to Short Barreled Rifles (SBR), rifles with a barrel under 16″ long. However many people buy the 14.5″ barrel and permanently attach a 2″ flash hider to maker the overall length over 16″ and legal without an NFA tax stamp
AR15 Barrel Profile
- ‘Hollywood’ : ArmaLite Early AR-15 ultra-lightweight turned-down profile barrel, 1:14 twist
- A1: Government-specified barrel profile increased to between 0.675 and 0.575 inches “lightweight” or “pencil” profile.
- A2: Thin barrel under handguards, barrel in front of handguards is thickened to 0.715 inches. “Government Profile” or “gov’t profile”
- HBAR: A barrel that is thicker than government-profile
- M4 (14.5″ or 16″): section reduced to 0.575 inches to mount M203 grenade launcher
- M4A1 HBAR: 14.5″ M4 barrel thickened under handguard for automatic fire
- Super Heavy: Special target / match barrel
AR15 Gas System Length
Three common and a shorter pistol length. Standard gas system lengths are; carbine, mid length, rifle
AR15 Barrel twist
- 1:14 1 right hand twist every 14 inches
- 1:12 1 right hand twist every 12 inches (305 mm)
- 1:10 1 right hand twist every 10 inches
- 1:9 1 right hand twist every 9 inches
- 1:7 1 right hand twist every 7 inches (177.8 mm)
More on the way
- Chrome lined chamber and bore
- AR15 Fluted Barrel
- headspacing
- Cold Hammer Forged barrels
- Stainless Steel
- Government Profile
- HBAR
- Barrel marking
- barrel nut
AR-15 Barrel Parts List
- Barrel
- Barrel extension
- delta ring
- barrel nut
- Gas tube (carbine, mid, rifle)
- Weld Spring
- Gas tube pin
- Snap Ring
Changing the barrel on an AR-15
AR15 Barrel Length & Profile Comparison
