Product Spotlight - Brownells BRN4 HK416 Bench Block

Synposis

In this video, Steve and Caleb from Brownells introduce a brand-new tool designed specifically for AR builders and HK416 enthusiasts—the Brownells Bench Block for BRN-4 and HK416 barrels. If you’ve ever struggled to remove or install gas block pins while keeping your barrel safe and secure, this tool is the solution.

What You Will Learn

The Brownells BRN4 HK416 Bench Block video educates viewers on the tool’s ability to securely hold and position BRN-4 or HK416 rifle components for precise assembly and maintenance. It highlights the bench block’s role in addressing the unique design challenges of these platforms and provides practical gunsmithing tips for effective use, including alignment, part installation, and troubleshooting.

Benefit

This video serves as both an educational resource and a product demonstration, equipping viewers with the knowledge and tools needed to enhance their gunsmithing skills for specialized AR platforms.

Unboxing the Bench Block

Caleb kicks off the video with a quick unboxing—though he admits he already tore into it out of excitement. The block comes in basic plastic packaging, and what you see is what you get: a purpose-built, heavy-duty polymer bench block designed to support your barrel and gas block during installation or removal.

Purpose of the Tool

The main function of the bench block is to support your barrel while you install or remove the gas block pins, specifically on:

• BRN-4 barrels

• HK416 barrels

• M27/M38 profile barrels with bayonet lugs

• Gas blocks with front sights or adjustment knobs

This is not a universal AR-15 block—it’s tailor-made for the unique profiles of the BRN-4 and HK416 systems.

Using the Bench Block

Caleb demonstrates how the tool works by first moving his coffee out of the way, then placing the bench block on the workbench. It features a textured underside that keeps it stable during use.

After removing the piston (a necessary step before beginning), Caleb lays the barrel assembly into the block. Once the barrel is cradled in the correct orientation, you can safely drive out or install the gas block pins without the barrel shifting or the finish getting damaged.

Compatibility and Design Details

One of the standout features of this block is its precise fit for M27/M38 barrels, which include a bayonet lug cutout. It’s also designed to accommodate HK416 gas blocks that have:

• Built-in front sights

• Adjustment knobs for the gas system

Steve points out that using this tool is a huge improvement over the old method—trying to wedge your barrel into a standard bench vise with soft jaws and hoping for the best.

Material and Build Quality

Caleb and Steve both highlight how dense and solid the block feels. Though it’s made of non-marring polymer, it’s much heavier than expected due to its high-density composition. That weight helps keep the block in place while you work, and the non-marring surface ensures you won’t damage your barrel finish—a major consideration when working on a high-end HK416 or BRN-4 build.

Added Features – Punch Storage

Built into the side of the bench block are slots to hold your roll pin punches. This added convenience helps you keep your tools close at hand and organized during the gas block installation process.

Why It Matters

As Steve puts it, if you’ve spent the money to invest in a 416 or BRN-4 setup, you don’t want to risk marring your barrel or misaligning components by using the wrong tools. The bench block gives you a safe, secure, and repeatable way to work on your barrel.

This tool is ideal for:

Installing a new gas block

• Removing a factory one for upgrades or service

• Ensuring alignment without damaging your parts

Final Thoughts

Caleb and Steve agree that the Brownells Bench Block for BRN-4 and HK416 is a simple but highly effective addition to any builder’s bench. It’s designed specifically for HK-pattern barrels, built from non-marring, heavy-duty polymer, and includes integrated punch holders to streamline your workflow.

If you're working on a BRN-4 upper or building out a 416 clone, this tool is well worth adding to your kit.

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