The mAh rating you get while charging isn't always the true capacity of the cell. The only true way to measure a cells capacity is under discharge.
A deadshorted 3300 will be peak in the 3900-4000 mAh while a non deadhsorted one will peak in the 3400-3500 range. Under discharge a deadshorted 3300 will have 330 seconds of runtime at 35 amps and non deadshorted one will have 355 or so.