Brownells AR-15 Bolt Extractor Spring O-Ring

The Brownells AR-15 Bolt Extractor Spring O-Ring is a small but critical replacement part for the AR-15 bolt assembly. This black rubber O-ring fits over the extractor spring to provide additional tension and buffer, helping to ensure reliable extraction and ejection. A common upgrade or replacement part for AR-15 builders and gunsmiths, it is compatible with standard AR-15/M4 bolt carrier groups.