RCBS electronic scale.

[Mountain Guy]

Howdy.
Had my first go round with a new RCBS electronic scale ( 750 )
Not sure.... I calibrated it and started loading bullets. After every charge it would not go back to zero.
I would just hit the zero button and do a new charge.
Is this right ?
Or are you supposed to re-calibrate every time.
I loaded a bunch and got to thinking afterwards that may not be correct.
Neither the instructions or their website make any reference to what to do when it doesn't go back to zero on it's own.