US Patent 11619119 Downhole gun tube extension

A gun-tube extension has (1) a body portion, (2) a first end configured to connect to an end cap of a gun tube, and (3) a second end configured to be connected to a sub-assembly. The gun-tube extension may rotate either by the operation of gravity on weights or by a motor. The gun-tube extension may include an orientation-detection device, such as an accelerometer, which may be part of an addressable switch. A ground for a gun tube or gun-tube extension may include a bow spring attached to and in electrical communication with the gun tube housing or the gun-tube extension housing. An end cap may include indexing indicia to orient a gun tube to a desired rotational position and/or may be structured to fit different diameter gun tubes.