This sounds like the same problem with my Excalibur. Only that one has Humphrey Solenoids, and a brand new Tadao Ebisu board. Spent over 200 dollars trying to fix it(o-ring kits, new solenoids, new board etc.) gave up and sent it in to Destructive Customs. Other suggestions that point towards the issue from what others have told me on this forum are:
1) Replace o-rings on your bolt. I had random bolt stick until I realized that the front oring was worn out and getting caught.
2) Replace all o-rings in the hammer and ram cartridge. Gunky cartridges are bad mmmkay.
3) Re-crimp your solenoid connectors. Bad connects = inconsistent power. The front solenoid is for the bolt.
4) Clean your solenoid piston.
5) You may not need new solenoids but you do need to get the service tools and become intimate with the manual.