A method and apparatus for intentionally slowing the speed at which detachable ammunition magazines can be interchanged in a firearm receiver. A magazine catch assembly includes a latch adapted to engage a recess of a standard magazine in the magazine well. An input pad receives an input signal from a user that initiates a count-down sequence. When the count-down sequence is finished, an actuator mechanism is displaces the latch to disengage the magazine for replacement. Return of the latch to the engaged position may be automatic or user-initiated. The count-down sequence may be electronic or manual. User input may require use of a specialized tool. The latch may be spring-biased toward the engaged condition. The input pad may be responsive to an authoritative wireless over-ride signal to remotely disable the firearm.