The materials that an object is made of can be very important. Eugene Stoner and his creation, the AR-15, proved this by using materials like aluminum and plastic composites on the rifle instead of the steel and wood that had been used since the early days of firearm construction. There are many different options for materials, and depending on what it is being used for often helps determine which are best to use. For the Bolt Carrier Group, the hardest working part on the AR, the material used to make it may be the most important of any part.
Since the BCG works so hard it is important that it is made out of materials that can hold up to the rigorous demands placed on it. That is why the Mercury Precision Nickel Boron Bolt Carrier Group is a great item to consider when looking for a BCG. The underlying material is Carpenter 158 Steel which is important given the things the BCG must do. It chambers new rounds and contains the firing pin, which fires the rounds, in the center of the BCG. The bolt head needs to be strong, so this one is made with a high-carbon steel, which has a high core hardness and high fatigue strength. Having tough material that will last gives value to this part.
The Nickel Boron coating on this is what makes this a next-level BCG. This coating makes it more reliable and resilient with high resistance to wear and corrosion. Due to the chemical composition of the special coating, it naturally experiences less friction. Although it does work better with no lubrication than other finishes, we definitely recommend that you lubricate this part, though you may need less than with another finish.
Cleaning this is much better as well since everything wipes off very easily. Dirt and fouling are easy to see against the color. This makes it great to use on an AR pistol or if you are using a sound suppressor as you tend to get more fouling due to the short length of the gas tube or the blowback of more of the gases from firing. It's easy to see what you're cleaning also, with dirt and fouling readily showing up against the color.
A lot of people also feel the Nickel Boron looks better. Seeing the beautiful finish showing through the ejection port and contrasting the rest of the upper receiver can help you and others appreciate the look of your AR. It’s also unique, something that will set your AR apart.
This particular BCG is meant for a gas impingement system and is good for the calibers .223 Rem, 5.56 NATO, .300 BLK, and .350 Legend. You can use it with any of these with no changes or modifications between uses. We also have an LR-308 version which is compatible with 6.5 Creedmoor and .243 Win. Both of these have forward assist notches so they work for either a forward assist or non forward assist compatible upper.
