Solution for possibly under-gassed 18" Rifle length gas.

[C Ward]

The gas block can be on and tight and still be misaligned , most gas blocks are designed so the spacing allows the original 2 piece hand guards to be installed . If the gas block is seated against the barrel shoulder it can block the port partially, only way to know for sure is too tear it apart and measure.

The buffer and BCG are typically weight matched to prevent / mitigate bolt bounce and the BCG driving the buffer in to the back of the buffer tube and coil binding the recoil spring . They usually need to be reduced in mass together.

[SA Friday]

It should cycle without having to open the port up. Bring it in and we can measure the gas port and go through the system. It sounds like you are either losing gas somewhere or losing energy from some sort of binding.