Links to popular troubleshooting and tuning topics:
Barrel troubleshooting and accurizing for the DIYer (and an example)
Bore lapping versus polishing and fire lapping versus cast lap
Barrel crowning - brass screw method
Barrel machining
Barrel machining - reamer selection for leade
Adjusting a regulated PCP
Regulator creep, contributing factors, and how to deal with it
Re-sealing a Huma style regulator
Regulator recovery time and related troubleshooting
Regulator pressure changing with the reservoir pressure
Scope installation - eliminating cant error
Barrel troubleshooting and accurizing for the DIYer (and an example)
Bore lapping versus polishing and fire lapping versus cast lap
Barrel crowning - brass screw method
Barrel machining
Barrel machining - reamer selection for leade
Adjusting a regulated PCP
Regulator creep, contributing factors, and how to deal with it
Re-sealing a Huma style regulator
Regulator recovery time and related troubleshooting
Regulator pressure changing with the reservoir pressure
Scope installation - eliminating cant error