BRN-4: You Could Create a Fossil
This video from Regular Guy Training LLC, featuring the BRN-4, delves into the practical differences between piston-driven and traditional direct impingement AR-15 systems regarding carbon fouling and long-term reliability. The instructor, demonstrating expert-level knowledge, highlights how piston systems maintain a cleaner action for significantly more rounds, contrasting it with the fouling inherent in direct impingement designs. The discussion also touches upon potential storage-related issues in piston ARs after extensive suppressed use.









