Box by Pin Perforating Gun System

A perforating gun system comprising:

• a first gun body having external threads at a first end and internal threads at a second end;
• a cartridge holding a detonator;
• a switch within the cartridge electrically connected to the detonator;
• a shaped charge loading tube having an upper end and a lower end;
• at least one insulator between the shaped charge loading tube and the gun body;
• an upper end fitting on the upper end of the shaped charge loading tube;
• a detonation transfer sub on the lower end of the shaped charge loading tube;
• a lower end fitting on the lower end of the shaped charge loading tube;
• an upper insulating cap on upper end fitting;
• a lower insulating cap on lower end fitting;
• and
• wherein the upper and lower end fittings are conductive, the cartridge has an electrical contact proximate to the detonator, and the lower end of the loading tube has an electrical contact adapted to contact the electrical contact proximate to the detonator.

A perforating gun system comprising:

• a first metallic gun body;
• a first shaped charge loading tube;
• a first insulator between the gun body and the loading tube;
• a cartridge holding a detonator and a switch;
• and
• a detonation transfer end fitting coupled to at least one end of the first shaped charge loading tube further comprising:
• a cylindrical outer housing with an upper end and a lower end and a cylindrical axis;
• a first bore of a first diameter along the cylindrical axis with a first end being the upper end and a second end, adapted to accept detonating cord;
• a second bore of a second diameter along the cylindrical axis starting at the second end of the first bore and having a third end adapted to accept a detonator,
• wherein the first bore intersects the second bore at the second end.

A ballistic transfer housing comprising:

• a detonation containment body having an outer surface, a first end, a second end, and being substantially cylindrical about a longitudinal axis;
• a ballistic transmitter bore extending into the body along the longitudinal axis from the first end;
• a ballistic receiver bore extending into the body along the longitudinal axis from the second end;
• a ballistic transfer bore extending from the ballistic transmitter bore to the ballistic receiver bore;
• and
• an inspection bore extending into the body from the outer surface and intersecting the ballistic transmitter bore, the ballistic receiver bore, or the ballistic transfer bore.