A perforating tool including a body, a first lid and a second lid, the first lid attachable to one end of the body and the second lid attachable to an opposite end of the body, to define an interior cavity of the body. The interior cavity has an air-tight seal with an exterior environment surrounding the body. In some aspects, one or more plates are disposable within the interior cavity such that the one or more plates are situated apart from an explosive charge when the explosive charge is disposed in the interior cavity, the one or more plates occupying part of a total interior volume of the interior cavity and thereby reducing a free interior volume inside the body. In some aspects, two or more plates are disposable within the interior cavity such that the two or more plates are situated apart from an explosive charge when the explosive charge is disposed in the interior cavity, the two or more plates occupying part of a total interior volume of the interior cavity and thereby reducing a free interior volume inside the body.