Let it run in for say 500 shots.If you put too much gun grease on the spring etc that will impair the perfromance.I just use my finger and smear LT2 along the spring.Do not put any lube in front of the piston seal.If you are not careful when inserting the piston into the tube you take a chunk out of the piston seal on the cocking guide 'cut out'.This will impair the performance also.
CDB