M4 Reassembly

[Trojan]

Hmm I've reassembled the gun a few times and had this problem before, I've forgotten how I fixed it but for some reason right after I pull the charging handle over the notch it gets stuck right before it can slot in.

 

Any ideas of whats blocking the Upper to attaching into the lower

 

http://i.imgur.com/efvyzNx.jpg

http://i.imgur.com/hEJDEJJ.jpg

http://i.imgur.com/7fxTxMp.jpg

[Samurai]

Pull the charging handle a bit.

[Trojan]

god damn it hahha all that trouble...

thanks though