Does my reg piston need replacing?

[Handyman]

When I fire my RT, a tiny puff of air shoots out the back of the velocity adjuster nut. Is this normal, or does it mean my reg piston assembly need replacing?

Thanks

[Handyman]

Anyone?

[BlackVCG]

If you don't hear a constant leak, it's working fine.

[Tunaman]

I just built a Mag that did the same thing. In all my years of building them, I have never ran across this one before. I did swap out the Reg Piston and it stopped.