Product Reviews for PJARSTKCP-B - AR-15 M4 Stock Lock Pin AR-15 M4 Stock Lock Pin by GS (2024-10-25 14:00:11) Rating: 5 / 5 - 5 - Excellent Owned Product for: less than 1 year Pros: This AR-15 M4 Stock Lock Pin works great for California Featureless are builds. Cons: Other thoughts: