Originally Posted by CrazyHarry
Fairly certain its from the sail area, unless another leak has developed over the short time I've had it... and I CERTAINLY don't understand why shooting the marker would seal it if it was the noid. That behavior makes me think it's one of the orings that are moving.
There is a spool inside the solenoid with dynamic o-rings just like the bolt, though obviously smaller. So it's not crazy to think it could behave in the same way.
The bolt sail o-ring is definitely a more common cause for a leak through the frame, but if you replace it and the leak persists, I would move on to another possible cause.
Of course if you are talking about bolt TAIL (leak from back cap) that is an entirely different story.