The Next Level AR10 Firing Pin Retaining Pin evolved from our desire for better quality parts. During the testing phases on our 308 BCG we tried several variations of retaining pins. All of them were very weak solutions for the application and they often broke after extended use. Therefore we went to work and designed these retaining pins. We machine our pins in house on our lathes to exact tolerances from 4140ph steel bars. They are then Nextride coated for a long lasting, solid upgrade to any 308/AR10 BCG.