Looking at the first pic the (down the line) you can see the very last section of the body that holds the gas cylinder retaining pin is out of square/canted with the gas shield,notably the barrel key way.If the body was twisted these two items should still be in line ?

Pull the gas cylinder and remove the gas deflector to see whats going on with the location tangs.

The L4 gas deflector is not listed in the IPL but is MG 4971



ATB KG