Originally Posted by Dodger21
So is there anything I can try that is simple or straight forward and doesn’t mean taking the rifle apart?
As someone has said a new o ring on the port may sort it. If not then a shim under the port maybe needed, simply remove the port, 4mm allen key, and make up a washer/shim from some thin plastic sheet and reassemble
as said elsewhere on the thread, you will get a small air blast from the stabiliser but that's from the top of the bolt if the blast is from the sides it's the port