This expert-level guide from School of the American Rifle details how tolerance stacking can cause M4 feed ramp issues, even with high-quality parts. It visually demonstrates how barrel extension ramps can overhang receiver ramps, leading to feeding failures evidenced by copper residue. The guide outlines the diagnostic process and the necessary gunsmithing steps to correct this common AR-15 problem.
You've reached the end! 1 videos loaded.
Gun Laws by State
Read firearms regulations for all 50 states + D.C.
Find Gun Dealers
Search licensed FFL dealers near you.
