Folks, Primary Arms has WMD Nickel Boron bolt carrier groups (BCGs) on sale and in stock! These are my favorite AR-15 BCGs and I always recommend them. Note, they make a .308 BCG but I haven’t tried one yet.
Their Nickel Boron coating is excellent the lubricity is superb – even without any oil they move very freely. They also hold up great as well.
The following specs are from WMD’s website:
- Bolt – Carpenter 158 heat-treated, shot peened and magnetic particle inspected. Manufactured to government drawings. Milspec gas rings. NiB-X coated (40% more wear-resistant than chrome).
- Extractor – Manufactured, heat treated, and hardened per government drawings. Black extractor buffer and heavy-duty spring. NiB-X coated.
- Firing Pin – Manufactured, heat-treated, hardened, chromed and certified per government drawings.
- Carrier – AR-15 or M16 style (heavy weight), 8620 material, heat treated and case hardened. Manufacturing tolerances on inside diameters tightly controlled. NiB-X coated for durability and ease of cleaning.
- Gas Key – Hardened to USGI Specifications and attached using knurled grade 8 hardened fasteners. NiB-X coated. Staked per military specifications. The knurled screw heads further enhance the effectiveness of the staking.
- Cam pin – Manufactured, heat treated, hardened and certified per Government drawings. NiB-X Coated.
- Hammer – Manufactured, heat treated, hardened and certified per government drawings. NiB-X Coated. Can be semi-auto or full-auto.
The photo above is of the WMD BCG in my 10.5″ AR pistol. Here are a few more photos for you as well.






So if you are shopping for a BCG – definitely check these out – click here to open the Primary Arms page! I hope this helps you out – these really are my favorite BCGs for the AR-15.
Please share the link on Facebook, Forums, with colleagues, etc. Your support is much appreciated and if you have any feedback, please email us in**@*********ps.com. If you’d like to request a report or order a reprint, please click here for the corresponding page to open in new tab.