The air actually leaks from inside the adjuster- ie it pushes on the allen key. The only way I can see that happening is that is it leaking around the seat and not what is holding it.
I actually just took out the adjuster to double check and when I put it on my tester to adjust the pressure it leaked a little then went away?? After I put it on the gun it doesn't leak now?? I did nothing different.
Are you saying there is an interior o-ring in the seat holder?
I thought it was the seat itself that made the seal.
Edit: Took out the seat and looked down in there and yes I see it, albeit tiny as hell! A little dow 55 seems to have done the trick-didn't have any 6 x 1s laying around.
Thank you very much for pointing that out.