Quote Originally Posted by factoid
Pushing the bolt does stop the leak.

The sear I'm using is brand new, though, so I'm not sure what I can do to affect how far forward the bolt sits.

Maybe a piece of scotch tape inside the sear pin groove on the rail? Maybe that would allow the sear to sit a bit farther back?

This same rail was used on for a while on my classic valve with level 10 and it had a similar problem. But with that valve I could correct the leak by using a shorter spring.
Well, if you are using a rail bushing, and I assume you are, then you have a rail that is out of spec. I wouldn't go with the scotch tape idea. The sear pin is usually tight as it is. You might be able to press fit a solid slug into the rail bushing hole and drill the hole in it so it is forward of where it normally sits. That would push the valve farther forward.

What might work, is if you shave a tiny bit off the inner flat edge of the powertube tip. Its the flat surface that pushes against the carrier. Taking a bit off it will allow the carrier to sit farther forward. Make sure you do it against a flat surface so you don't sand more off one side than the other.

The other option is to shave a bit off the carrier itself. The problem with this option is that it only works on the one carrier. If you have to make a change for any reason, you will have to do it again for the next carrier, and then the carriers won't be interchangeable in other guns.