Brownells Brn-180 Gen 1/2 Adjustable Gas Block, 300 Aac Blackout

The Brownells BRN-180 Gen 1/2 adjustable gas block for .300 AAC Blackout gives you real control over your modern retro rifle's performance. Unlike fixed gas systems, an adjustable block lets you dial in the right pressure for your specific ammunition, suppressor setup, and shooting conditions—crucial when you're running subsonic rounds through a can or pushing supersonic loads at the range. This is the tuning component serious BRN-180 builders reach for when they want the rifle to run clean, soft, and reliable without over-gassing.

Built for the BRN-180 upper receiver platform, this adjustable system handles the .300 Blackout's unique demands. Whether you're loading subsonic hunting rounds, supersonic defensive ammo, or range brass, you can adjust gas flow to match your ammunition and suppressor status. The modular design includes a gas nipple, gas cup, and retaining clip, giving you the pieces needed to set up a tuned gas system rather than guessing with a fixed setup.

Brownells makes this kit for shooters who understand that a well-tuned gas system isn't a luxury—it's the foundation of reliable, low-maintenance performance. If you're building or upgrading a BRN-180 in .300 Blackout and want the flexibility to optimize function across different ammunition types and suppressor configurations, this adjustable block is the right move.

Key Features

• Adjustable gas system for fine-tuning performance to your ammunition and suppressor setup
• Designed specifically for BRN-180 upper receivers in .300 AAC Blackout
• Includes gas nipple, gas cup, and retaining clip for complete modular system
• Lets you optimize function for subsonic and supersonic loads

Specifications

Frequently Asked Questions

Will this adjustable gas block work on my BRN-180 upper?

Yes, this kit is designed for the BRN-180 upper receiver platform in .300 AAC Blackout.

What's included in the adjustable gas system kit?

The kit includes a gas nipple, gas cup, and retaining clip—all the components you need for a complete adjustable gas system setup.

Can I use this with a suppressor and subsonic ammunition?

Yes. The adjustable design lets you tune gas flow for subsonic ammunition when running a suppressor, as well as for supersonic loads—giving you flexibility across different shooting scenarios.

How is an adjustable gas block different from a fixed system?

An adjustable gas block allows you to dial in the exact amount of gas your rifle receives, letting you optimize performance for your specific ammunition, suppressor setup, and firing conditions. A fixed system delivers one preset amount of gas, which may not be ideal for all loads or configurations.