Tuning a rifle to perform across different configurations can be challenging, especially if you’re switching between supersonic and subsonic ammo or using a suppressor. In this story, we’ll see what it takes to tune the CMMG Banshee 300 BLK with the Ultradyne Quantum Adjustable Gas Block, to give us the best shooting experience.
Disclaimer
Ultimate Reloader LLC / Making with Metal Disclaimer: (by reading this article and/or watching video content you accept these terms). The content on this website (including videos, articles, ammunition reloading data, technical articles, gunsmithing and other information) is for demonstration purposes only. Do not attempt any of the processes or procedures shown or described on this website. All gunsmithing procedures should be carried out by a qualified and licensed gunsmith at their own risk. Do not attempt to repair or modify any firearms based on information on this website. Ultimate Reloader, LLC and Making With Metal can not be held liable for property or personal damage due to viewers/readers of this website performing activities, procedures, techniques, or practices described in whole or part on this website. By accepting these terms, you agree that you alone are solely responsible for your own safety and property as it pertains to activities, procedures, techniques, or practices described in whole or part on this website.
CMMG Banshee 300 BLK
The CMMG Banshee 300 BLK is an 8.5-inch barrel powerhouse. I really enjoy shooting this AR, but when transitioning between Berry’s heavy subsonic 220-grain bullets and lighter supersonic rounds I’ve experienced some different results. Adding or removing a suppressor complicates things further. For the Banshee to perform its best we can do some testing, and tuning.
AR Gas Systems
At the heart of an AR’s functionality is its gas system. Gas is siphoned from the barrel through a port, redirected into the gas block, and then used to push the bolt carrier group (BCG) back to cycle the action. Fixed gas systems are fine for most simple setups and scenarios, but they aren’t very flexible. This is where adjustable gas blocks, like the Ultradyne Quantum Adjustable Gas Block, shine—offering a way to fine-tune gas flow to suit your specific needs.
Ultradyne Quantum Adjustable Gas Block
The Ultradyne Quantum Adjustable Gas Block brings flexibility and tunability to AR owners. Here’s what makes it standout:
- Adjustability: The tactile clicks allow for precise adjustments, making it easy to track and replicate settings.
- Compatibility: Designed to fit 0.625-0.936 size AR barrels
- Ease of Installation: Straightforward and easy to install, even for DIY gunsmiths
Whether you’re transitioning between muzzle devices or ammo types, the Ultradyne Quantum gas block is a good way to go.
Installation Process
Installing the Ultradyne Quantum Adjustable Gas Block is straightforward. I set up the Arrow Products Rock Vise; this vise is a solid and adjustable work holding solution. The process involves:
- Removing the factory gas block and transferring the gas tube to the Ultradyne unit.
- Aligning and securing the new gas block.
- Reassembling the rifle and ensuring proper alignment through the upper receiver.
With everything in place, the Banshee was ready for testing.
Testing with the Ultimate Reloader Recoil Rig
To capture detailed performance data, we turned to the Ultimate Reloader Recoil Rig.
At the heart of this system is the Dewesoft Sirius DAQ module, capable of sampling at 200,000 samples per second with 8-channel capability.
Recoil force was measured using a PCB Piezotronics load cell, providing precise insights into the rifle’s behavior.
We focused on two recoil phases:
- Primary Recoil Impulse: As the bullet travels down the barrel and exits.
- Secondary Recoil Impulse: When the bolt carrier group reaches the buffer and rebounds.
Results of Supersonic vs. Subsonic Testing
To kick off the testing, we started with our Berry’s 220gr subsonic load. Right away we noticed the secondary recoil event was not substantial at all – in fact, it was quite minimal. This load we tried wouldn’t cycle at all with the gas block wide open. Then, even upon increasing the powder charge, the second event was still fairly mild.
From here, we took our 175gr Supersonic load and tested it as well – pinning them up against one another. The supersonic ammo clearly had a larger secondary recoil event. Based on that result, we can assume that the subsonic load doesn’t need much work – the recoil is already minimal in comparison. So, we decided to tune that supersonic load to see how much we could reduce the recoil.
Dialing In the Gas Block
The tuning process with the Ultradyne Quantum Adjustable Gas Block was straightforward:
- Start with the gas block fully open (20 clicks).
- Fire a shot, record the data, and close the gas block by two clicks.
- Repeat the process until reaching a balance between reduced recoil and reliable cycling.
The sweet spot for the supersonic loads was identified at 8 clicks open, where the rifle cycled reliably, and the bolt locked back on an empty magazine. This setting provides a buffer for environmental variables, ensuring consistent performance.
Closing Thoughts
Through this project, we’ve seen how the Ultradyne Quantum Adjustable Gas Block enhances the performance and versatility of the CMMG Banshee 300 BLK. Whether you’re transitioning between subsonic and supersonic ammo or adding a muzzle device, this upgrade ensures your rifle is up to the task.
Have you tried an adjustable gas block on your AR? What challenges have you faced, and how did you address them? Let’s keep the conversation going—drop a comment and share your experience!
Get The Gear
Don’t miss out on Ultimate Reloader updates, make sure you’re subscribed!
Thanks,
Gavin Gear