Failure to eject??

[killshot44]

Is that from a new upper? Try scrubbing clean the chamber, looks like residue has built up in your chamber and causing casing to stick and not eject.

This.....carefully degrease/clean the chamber and bolt.

[MUNCHIE]

Well I cleaned it really well and oiled it last night, took it back to the range...same stuff so I found a local gunsmith who works on AR's. He replaced the extractor spring and changed it to the blue buffer, he also fixed a leak at the gas block. The gun now cycles but still doesn't lock the bolt back after the last round is fired. He said that everything in there looked cheap, namely the bolt but he told me to put some rounds through it and see if the pressure builds up a little after the carbon helps to seal the gaps.

[Nathan Krynn]

Who made the upper?

[MUNCHIE]

It is a JD machine upper with a wilson arms barrel and I am not sure about the bolt. It was supposed to have been an MP but I cannot see any markings

[Nathan Krynn]

MP?

[MUNCHIE]

Maybe M&P hell I don't know, what is a good BCG to replace it with if I decide to upgrade it?

[Brown Rock]

Maybe M&P hell I don't know, what is a good BCG to replace it with if I decide to upgrade it?

BCM.

[Nathan Krynn]

It is hard for me to answer that without sounding greedy as I sell them.

Mine are off the same production lines going to .mil

There are several good companies out there though.