the primer cord 49 also prevents loss of performance of the shaped charges 27 due to charge interference or nonsequential firing a carrier housing tube bore 51 with an axis not shown which is perpendicular to the axis of the carrier housing tube 17 is located on the carrier housing tube 17 of the perforating gun 11 and has a diameter slightly less than that of the base 34 of the charge liner 43 the carrier housing tube bore 51 extends to a depth about half way through the carrier housing tube 17 from the outside edge 13 of the carrier housing tube 17 leaving a selected unbreached portion 54 in the carrier housing tube 17 referring now to fig2 and fig3 in the drawings a plurality of shaped charges 27 in schematic here are shown assembled in the charge holder tube 19 in phase between about 135 and 145 degrees in the preferred embodiment a plurality of apertures 52 are milled with a phasing between about 135 and 145 degrees through a tube preferably a drawn over mandrel dom tube by a multiple axes laser milling machine or any other device known in the art for milling apertures in tubes fastener ring slots 53 are cut by a laser milling machine or any other device known in the art into the the top and bottom edges of the apertures 52 in the charge holder tube 19 to receive the fastener ring 45 of the shaped charges 27 the shaped charges 27 are inserted into the charge holder tube 19 and held in place by the fastener rings 45 with a pressure fit into the fastener ring slots 53 the primer cord 49 is fed.