[e-luder]

If your Nineball piston head is the DYNA one, the red one with all the holes, it's supposed to be loose. The idea is that the O-ring is self expanding once gas enters the loading muzzle and piston head kicks in. The piston head will kick in the seals when gas travels inside those holes and blow the oring up from beneath thereby creating the "perfect" seal.

I think you might actually have an issue with the Nineball gas routers. If they are too raised, they can impede the stroke of the slide because the loading muzzle will have a hard time passing it.

The ninball buckings have definitely declined in their quality these days. The casting mold they use and how old and worn it must be is definitely showing. A lot of those that i received looked exarcly like the ones you pictured. So it might not be the loading muzzle at all. In fact i cant see it being the cause of that issue.