308 AR Bolt Carrier

August 2016 – As I update this “308 AR Bolt Carrier” webpage I am a little overwhelmed by the sheer volume of companies offering 308 bolt carrier groups. I would caution anyone about using no-name, inexpensive generic BCG’s.

This page only applies to standard gas operated .308 AR type rifles. Piston driven AR’s will be covered elsewhere.

Dimensionally Armalite and DPMS bolt carriers groups are nearly identical to within a few thousandth’s of an inch of each other. This means they are interchangeable. However the one thing to keep in mind is you cant interchange the bolts between the different brands of bolt carrier. This means only use an Armalite bolt in an Armalite bolt carrier and a DPMS bolt in a DPMS bolt carrier.

Aero Precision M5 Bolt Carrier Group

Brownells AR 308 Bolt Carrier Group

Prime Weaponry 308 AR Bolt Carrier Group

CMMG 308 AR Bolt Carrier Group

DPMS 308 AR Bolt Carrier

DPMS offers two variation. One with a standard mil spec finish and the other in hard chrome. DPMS also sells the individual components so you can build a bolt carrier group from the ground up. They also offer a hard chrome bolt that can be utilized with either of their bolt carrier offerings as well as the Fulton Armory and JP Rifles bolt carriers.

DPMS 308 AR Bolt Carrier

Fulton Armory 308 AR Bolt Carrier

Fulton Armory offers two versions of their bolt carrier. The first is a standard DPMS LR-308 type and the second is a modified version that features a side cocking handle installed. The side cocking model is only to be used with an upper receiver milled to function with the side cocking handle. Using the side cocking model in a standard upper will damage you and your rifle.

Fulton Armory 308 AR Bolt Carrier Exploded View

Fulton Armory Side Cocking Bolt Carrier Group

SI Defense 308 AR Bolt Carrier – SI DEFENSE is now FALKOR DEFENSE

Not to much information on these bolt carriers other then they aren’t available for purchase yet as they are still in their testing phase at SI Defense.

Armalite AR-10 Bolt Carrier

To the best of my knowledge Armalite offers one mil spec bolt carrier group and from all reports its made very well.

ArmaLite AR-10 Complete Bolt Carrier Group

JP Rifles JPBC-4 308 AR Bolt Carrier

JP Rifles offers a mostly stripped bolt carrier. The JP LMOS Bolt Carrier and Key is a low mass bolt carrier finished in black QPQ hard coat. It increases longevity and lends a naturally smooth surface. This bolt carrier must be used with an LR-308 bolt assembly, firing pin, cam pin and firing pin retainer.

JP Enterprises LMOS Bolt Carrier and Key AR-10, DPMS LR-308

Fail Zero EXO Coated .308 Bolt Carrier Group

We really want to like the Fail Zero product but they review poorly across the web.

This Bolt Carrier Group (BCG) comes fully assembled and ready to drop into most mil spec AR10 upper receivers. All critcal parts are coated with EXO Nickel Boron technology that provides permanents dry lubricity, extreme durability, increase wear and corrosion resistance. Our patented Nickel Boron coating will reduce friction and improve the overall performance of your rifle. Nickel Boron treated parts include: Bolt & Extractor (.308 compatible), Bolt Carrier, Extractor, Cam Pin, Carrier Key, Firing Pin

Brand -Fail Zero, Caliber / Gauge – .308 Win, Platform – DPMS, Bolt Finish – Nickel Boron, Bolt Material – 9310 Steel, Carrier Finish – Nickel Boron, Carrier, Material – 8620 Steel, Magnetic Particle Inspection – Yes, High Pressure Tested – Yes

Young Manufacturing 308 Chrome Bolt Carrier Complete – YM-308NFA

Like their signature 5.56mm carrier the .308  (308 AR) version has added surface area in the front of the carrier gives a tighter fit when the bolt is in battery for more consistent lock up. We heat treat, precision grind and hard chrome plate all of our carriers and bolts. The carrier is made from 8620. The bolt is made from 9310. Compatible with the DPMS style rifles that take the P-Mag. Weight 18 ounces for complete assembly.

LANTAC E-BCG .308/7.62X51MM Enhanced Full Auto Style Bolt Carrier Group NiB Coated

AR10 Full Auto Style for increased mass and lock time. Our new 308 BCG is precision machined from 8620 Steel with a 9310 Precision Hard Ground, Magnetically Particle Inspected Bolt. The entire carrier assembly is NiB, Electroless Nickel Boron coated with the patented, advanced UCT EXO process, unlike standard NiB coatings. This offers extreme lubricity with a friction coefficient of .02 and surface hardness of 82-85 Rockwell C.
The carriers patent pending design features unique shrouded and forward facing gas ports that have also been re sized so that gas is vented differently to a standard carrier. This results in a system that runs flatter with a smoother energy pulse.

LANTAC E-BCG

In addition the system also runs cooler and cleaner, there is also less pressurization of the upper receiver when running a suppressed barrel.

The flared boss at the tail of the carrier enhances the 308 BCG’s position within the buffer tube at the time of cycling and allows for a flatter more controlled reciprocation of the assembly. All critical dimensions are hard turned / ground after heat treat. All E-BCG’s feature the LANTAC CP-R360-H™ patent pending domed cam pin that is machined from 17-4PH Stainless Steel and hardened to H900 condition (45RC approx).

The ultra smooth head reduces wear within the upper receiver. The BCG’s weight helps to increase lock time with smoother operation. Gas keys are properly staked at four points and only grade 8 fasteners are used in assembly. The E-BCG’s forward porting and unique shape assist in reducing pressurization inside the upper receiver that can be caused by short barrel rifles running suppressors. However, it should be noted that the E-BCG™ is not a complete solution for this issue and all rifles are different. ‘Over Gassed’ guns will suffer to a larger extent from this problem.

• Weight 1Lb 2.1oz
• Forward Porting, Enlarged Vents.
• Balanced flared boss.
• 8620 Carrier, Heat Treated, Hard Turned.
• MPI 9310 Bolt, Hard Turned / Ground.
• NiB UCT EXO Coating.
• CP-R360-H Domed Cam Pin
• Mil-Spec Gas Rings
• Mil-Spec Staked Gas Key
• Grade 8 Hardened Fasteners
• All Hard Chrome surfaces are to MIL-STD-171 1.2.2.2
• Lifetime Warranty.
• Made in the USA.

Anderson Manufacturing 308 Bolt Carrier Group

The Anderson Manufacturing AR-308 M16 Bolt Carrier Group is manufactured 100% to military specifications. With a chrome lined, 8620 carpenter steel carrier, 9310 Super Alloy Steel bolt, and properly staked gas key, this full-shroud carrier group is perfect for you next .308 build.

Brand – Anderson Manufacturing, Caliber – .308 Win, Carrier Style – M16 / Full-Auto, Platform – AR-308 – DPMS, Bolt Finish – Phosphate, Bolt Material – 9310 Steel, Carrier Finish – Phosphate, Carrier Material – 8620 Steel, Extractor – O-Ring, Gas Key – Staked, Magnetic Particle Inspection – Yes, High Pressure Tested – No, Weight – 0.72 lbs.

WMD 308 AR NiB-X Bolt Carrier Group – Polished – DPMS Pattern NiBXBCG308

Black Rain Ordnance Nickel Boron Bolt Carrier Group 308 AR – DPMS Pattern BRO-BCG-308

P.O.F. Ultimate Bolt Carrier Group 308 AR NP3 Finish

P.O.F. Ultimate Bolt Carrier Group 308 AR

F-1 Firearms 7.62 DuraBolt Direct Impingement Full Auto rated AR10 Bolt Carrier Group BCG-GOLD

Radical Firearms Complete Nickel Boron 308  AR Bolt Carrier Group for, WMD Coating

Complete Bolt Carrier Group for 308 AR, DPMS pattern rifles. This complete bolt carrier group includes a complete bolt, properly staked gas key, firing pin, cam pin and firing pin retaining pin. Bolt is precision machined from 9310 steel, and the carrier from 8620. Hardened extractor is S7 tool steel. The complete bolt head features a Melonite finish for added durability and resistance to wear, the carrier has a Nickel Boron finish to ensure the smoothest possible action. Coated by WMD Firearms. Brand -Radical Firearms, Caliber -.308/7.62×51,Carrier Style – M16 / Full-Auto, Platform -AR-308 – DPMS ,Bolt Finish -Nickel Boron, Bolt Material -9310 Steel, Carrier Finish -Nickel Boron, Carrier Material -8620 Steel, Extractor -O-Ring, Gas Key – Staked, Magnetic Particle Inspection – Yes, High Pressure Tested – No

ADK Arms – 308/7.62 Bolt Carrier Group with Forward Assist Serrations, Nitride

ADK Arms tried and true 308/7.62 bolt carrier group is engineered and designed to the highest tolerances and military specifications and beyond. Our superior nitride QPQ finish ensures long term durability and lubrication.

ADK Arms is a facility providing state of the art, high end AR-15 and AR-10 Components to the gun industry. We provide service to sell products, manufacture to unique specifications, and redesign to your requirements. ADK Arms is your one stop source for standard and custom gun parts.

With over 30 years experience in the government arms manufacturing field we have the knowledge and resources to provide exceptional quality products. Parts are manufactured in the USA to the highest tolerances to ensure accuracy and smooth functionality. All parts are inspected to MIL-I-45208 which means if we were to find 1 defective part then every part would be suspect. Our quality and inspection practices are at the same level as what our Men and Women in uniform use in operations.

All components of our bolt carrier groups are manufactured in house to strict tolerances. We are a DOD government contractor with a state of the art CNC machine shop and inspection facility. ADK Arms BCG’s are sold to you direct from our facility.

Rainier Arms Ultramatch .308 BCG NIB

Match style DPMS Pattern Bolt Carrier Assembly designed to work with DPMS style barrel extension and compatible upper receivers. Always check compatibility prior to use in any firearm.

Carrier Specifications:

• Full Auto Carrier
• SAE 8620
• Heat Treated
• Shot Peened
• Nickel Boron Finish

• Bolt:9310 Steel
• Shot Peened
• Heat Treated
• Nickel Boron Plated

• Extractor:S7 Tool Steel
• Precision Machined
• Shot Peened
• Heat Treated

Extractor Components: Extractor Spring made of Music Wire (The best spring steel available) “Reliability post” exceeds MIL-SPEC. Made with OUR OWN multi-cavity mold with the highest grade of chemical and heat resistant rubber, VITON. Our Reliability posts are NOT commercially available. VITON Rubber “Full-Auto O Ring” made if you want the highest grade of chemical and heat resistant rubber.

• Extractor Retaining Pin:
• Precision Machined 4140
• Heat Treated
• Precision ground to diameter
• Firing Pin:Colt Full Auto Spec
• Machined 4140
• Heat Treated

ALPHA Nitride 308 Bolt Carrier Group

ALPHA Nitride 308 Bolt Carrier Group Complete M16 bolt carrier group assembly. All the major components have been QPQ Nitride treated (Carrier, Bolt, Extractor and gas key). Slicker and harder surface with 70 RC hardness. MPI tested and marked, shot peened 9310 steel bolt. 8620 Steel Carrier. Requires very little lubrication and has a very slick surface. Easier to clean. Side staked gas key with grade 8 fasteners.

Davidsons Defense Omega Manufacturing .308 AR LR-308 Bolt Carrier Group – Black Nitride Finish

Note – The description below is from the vendor. It was the worst written product descriptions I have ever read. I cleaned it a little but did not perform a rewrite.

The Davidson Defense Nib bolt carrier group is one of the finest available on the market for bolt carrier groups with a finish that is unmatched by WMD.
Each Bolt Carrier Group go’s through a rigorous process of Rockwell testing Mpi and Hpt Testing Then after that the bolt is sent to Wmd to apply one of the best finishes on the market smooth and unfailing making this the ultimate in Lr-308 bolt carrier groups and for a cost that is much less than comparable bolt groups of the same caliber.

Features full length forward Assist Cuts where this bolt group is designed to be above mil spec in every way. It is finish in the tough and long wearing Nickel Boron, superior for its wear and ease of cleaning. This bcg fits the lr-308 dpms pattern guns only Most guns are patterned after the dpms Lr-308 Design Most AR-308 rifles are Lr-308 format Rifles Only the Armalite is not. So this part will fit almost all .308 platform guns.

NOTE: This will not fit the Armalite AR-10

KAK LR-308 BCG DOUBLE EJECTOR (BOLT CARRIER GROUP) MPI

KAK INDUSTRY LR-308 COMPLETE BOLT CARRIER GROUP

• DOUBLE EJECTORS
• MPI TESTED AND MARKED
• NITRIDE FINISH INSIDE AND OUTSIDE
• WITH FORWARD ASSIST CUTS
• CORRECT AUTO SEAR TRIP LOCATION
• 9310 HEAD
• 8620 CARRIER
• FOR 7.62 NATO, .308 WINCHESTER OR SIMILAR
• INCLUDES O-RING EXTRACTOR HELPER TO RUN UNDER ALL CONDITIONS
• WILL WORK WITH DPMS FORWARD ASSIST OR REAR AERO STYLE FORWARD ASSIST

308 Bolt Carrier Group

DRD Complete Bolt Carrier Group .308 DPMS Pattern Nib-X Finish 308BCGNB

LBE Unlimited AR-10 Complete Bolt Carrier Group Phosphate Finish Matte Black AR10BCG

LBE Unlimited was developed to answer the needs of Elite Task Force team’s world wide who demand top performing gear with no room for error. Whether you are shooting in combat, competition or practice chose the gear that will not fail under pressure, LBE Unlimited. This particular LBE Unlimited part is a must have for the modern gun builder or shooting enthusiast. Great as a spare, or perfect for your next build this complete AR-10 bolt carrier group features a bolt, carrier, and a phosphated matte black finish.

Specifications and Features:
LBE Unlimited AR10BCG
AR-10 Complete Bolt Carrier Group
Made in the USA
Matte Black

Fits:
Standard AR-10 upper receivers

Magpul PMAG D-60