AR15 Bolt Carrier Groups

What is a bolt carrier group?

A bolt carrier group, or BCG, is essentially 6 components that make for one of the most critical components of your firearms. Those include the firing retaining pin, bolt cam pin, gas key, bolt assembly, carrier, and the firing pin. Regardless of caliber, if you are using an AR platform weapon, you’re going to need a bolt carrier group. Your BCG is what allows you to fire chambered rounds and is what also extracts spent casings so that a new round can be fed from the magazine and chambered. 

What is a good bolt carrier group for AR-15?

In general, you’ll find many companies rebranding bolt carrier groups made by Toolcraft or Microbest, those are two of our favorite manufacturers. That being said, we currently favor the Failzero Bolt Carrier Group, which is coated in black nitride, for its reliable performance and price that doesn’t break the bank. Having the black nitride also makes it easier to clean the BCG and it’s easier to keep it lubed over longer periods of time.

If you have a larger budget, we highly recommend the Sons of Liberty Gun Works BCG. SOLGW is known for their high quality products, intensive armorer courses, and is a leader in the AR15 space. 

Are all AR-15 bolt carrier groups interchangeable?

Yes, they are. You can run just about any BCG in an AR15 chambered for .223 Remington, 5.56mm NATO, or even .300 Blackout. This includes M16 bolt carrier groups as well. Of course, some brands will work better than others and how well it fits your head spacing or barrel will also depend on the brand. 

What is the difference between bolt carrier and bolt carrier groups?

The bolt carrier is simply a part of the BCG while “bolt carrier groups” refers to the entire assembly of parts that we call the “BCG.” 

Do AR bolt carriers wear out?

AR bolt carriers can certainly wear out. But it’s more likely that you’d have to replace the firing retaining pin or bolt assembly before you’d have to replace the bolt carrier itself. 

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