Nickel Boron Barrel Extensions for the AR Platform

Where many rifle designs have the barrel screwing to the front of the receiver, the AR platform is a little different. Here, the barrel has a screw-on extension with a pin that indexes on the receiver front, after which the whole assembly is fastened together with a threaded barrel nut. This barrel extension plays a critical role in several functions. 

WMD Guns has perfected nickel boron (NiB) as a firearm finish, and the properties of this coating make it particularly suitable for barrel extensions. We offer these parts for both AR-15s and AR-10s to promote optimal performance.

Our barrel extensions are cut with M4 feed ramps and are suitable for use in receivers with or without feed ramps of their own. Many of the barrels we sell come with an extension already installed. 

The Role of the AR Barrel Extension

In the typical operation of an AR-platform firearm, feeding happens as the bolt moves forward, whether that’s after a shot or upon manual bolt release by the shooter. The bolt face picks up a round from the magazine and pushes it into the barrel extension for chambering. 

As the round moves into the chamber, the bolt head enters the recess in the barrel extension and rotates to engage with the locking lugs for safe firing. 

When the shooter fires and the round’s powder ignites, the pressure from the fired projectile enters the gas system and pushes the bolt carrier back. The bolt rotates back and disengages from the lugs to unlock and continue its role in the process of firing. 

Advantages of an NiB Barrel Extension

Since so much of the AR platform’s operation is dependent on timing, it’s important that the barrel extension facilitate smooth, reliable movement of the lockup components. Our NiB-X® nickel boron formula, being naturally slick and exceptionally hard, is the perfect coating to support this objective.

A nickel boron barrel extension will minimize the risk of carbon buildup and withstand thousands of bolt cycles for excellent reliability. In fact, our NiB-X® coating stood up to a 30,000-round torture test without flaking or wearing through. 

A hard, slick coating is also exactly what you want in a part that supports the feeding process. We make our barrel extensions with M4 feed ramps to further facilitate fast, effortless feeding and keep your AR running strong. 

Order Premium AR-10 and AR-15 Barrel Extensions

Many AR parts perform their best with a high-performance coating, and the small but high-impact barrel extension is no exception. 

If you’re working on a custom AR barrel and want to prepare for success with even the small parts, add one of our nickel boron barrel extensions to your build. If you have any questions about our products or coatings, please get in touch with our experts.