Since it's diet requires nothing but lead and lubricant it's dirt cheap to shoot.
I'm getting dime sized groups (3-5 shots) with open sites at 6m. Quarter sized groups after my third cup of coffee

Anyway, after 250 or so shots it started to leak. So I loosened the set screw on the end of the piston, drifted out the pin and pulled the piston out. Cleaned the o-ring, piston and chamber with a paper towel, put 3 drops of Crosman Pellgunoil on the o-ring and slapped it back together.
Works like a charm.
If that's all this thing requires for maintenance then colour me impressed.
Does anybody else have any experience with these things? Is there anything else I should look out for (aside from the smaller pins working their way out but, I have a fix for that).