Ok only if the accuracy seems to be off. I really think it depends on what you are shooting (both ammo and barrel) and at what speed. I have a HW55 runs about 650 to 750 depending on pellet weight never cleaned. Still shoots one hole groups. I forgot to reset the hammer spring in Dad's Avenger, ran some Hades through at about 1000fps didn't take long to need a cleaning. We were eliminating destructive tree rats at 25 to 35 yards. That speed is not needed but was accurate at those distances. Till they weren't. I did try running slugs as fast as I could from my Cricket, that crapped it up in about 300, now some were the Grizzleys, some were the FX hybrids, some the NSAs, some those new Zahns.
If you know with x00 rounds accuracy starts a decline I would clean before that.
Jim