Here's a pic on how i fitted the national match barrel bushing to my norinco.
First you need to fit the new national match barrel bushing to the slide.
Then get the barrel to sit into full battery with no barrel spring.
Then i fit the bushing so the barrel can hinge from full battery lock up into loading the next round.
The loc up is offset allowing the barrel to hinge up and down again with no barrel spring in either position.
Yet it has 100% lock up with no movement when its in full battery,
Sorry for the poor drawing the "C" is more of a short "U" shape that wrapps about 50% around the barrel so it holds it firmly when its in full battery. With my norc shooting cloverleafs it proves it works.