GHK M4 Problems and Fixes | FREE Broken Feed Lip Fix!

0:00 - Problem 1 0:41 - Problem 2 1:00 - Problem 3 1:45 - Problem 4 1:56 - Problem 5 3:01 - Problem 6 3:34 - Problem 7 4:30 - Problem 8 5:11 - Bolt Lock Fix 5:29 - Bolt Filing 5:42 - Cracked Feed Lip 6:03 - Explanation 8:04 - Cracked Feed Lip Fix 9:08 - Testing the Fix The main culprit for this issue is a double feed originating from cracked feed lips. When two BBs go into the chamber at the same time this causes a jam which results in an expulsion of gas from the mag. This is bad for your mag because it will cause leaks as the gas router isn’t designed to expel a whole mag of gas in one go and could possibly freeze your internals causing damage to your nozzle, hop up chamber, and bolt. This is the worst case scenario for a double feed. If your stock plastic hop up is broken, your only option would be to buy a replacement hop up unit. You can opt for a metal one or replace it with a stock hop up unit which may break again. Just to explain what happened here when I was shooting the gun didn’t want to fire but when I pressed the trigger without the mag it fired. Most of these issues may be caused by the trigger group being jammed with pieces of BBs or other debris. For the bolt lock fix I did this to my rifle because it encountered this issues after a thousand or so rounds. Make sure you don’t hit the bolt lock too hard because mine now locks back with 1 BB left in the mag. I haven’t done this other fix since the bolt lock still works and I have another spare bolt, but it could help you if you have this issue.