WA GBBR M4 Bolt Carrier issue!
 

For some reason the bolt carrier locks back cocked but won't release. It does this sometimes. What is the cause of that?

I manage to get it to slide back and then I greased the shit out of it, and it still locks back after a few fires!!

I don't understand why it does this!

It sounds like your problem lies in the Lower receiver. Perhaps this is a FCG or bolt-catch assembly issue, and the bolt carrier is getting caught on the hammer or something.

I found the quick fix solution is by hitting the left side of the gun with your hand and it releases it.

How do I tell what the issue is with? The gun is less then 1 month old, gamed onced and it did this after 7hrs of play.

Are you sure its not just the bolt catch?

I'm not sure, it actually has a high chance of being the bolt catch. If that is the case, what is the solution? replacement? or just greasing?

When you pull back the charging handle and the bolt locks back, does the bolt release when you put the bolt catch?

it might be the buffer lock problem, when buffer lock it too high or too low it can cause the BCG to jam and when you tab the side of the gun it will be released, try pull the charging handle when the gun is pointing to the floor, and then pull it when it's pointing up, if pointing up jam the BCG then it's buffer lock problem.

Uh. Is your mag empty?

Does the BCG go too far into the buffer tube? Might need some spacers in the buffer to shorten the travel.

You are going to have to be more clear in order for us to help you.

Yes mag is empty, and when I hit the bolt catcher it does nothing. Like I said it gets stuck pulled back. I have to hit the gun on the side for it to release.

It works right now but once in a while it jams up, more often recently.