Retention member for perforating guns

An apparatus for perforating a wellbore, comprising:

• a charge tube;
• a carrier tube having an interior bore in which the charge tube is disposed;
• a plurality of shaped charges affixed in the charge tube, each shaped charge having a radially outward pointing post having a slot receiving a detonator cord having a circular cross-sectional profile;
• and
• a retention member associated with each post, the retention member including an opening for receiving the post, wherein the retention member includes a medial curved bridge portion that conforms to the profile of the detonator cord, the bridge portion being circumferentially adjacent to the post such that it inhibits axial movement of the detonator cord, substantially all of the retention member being radially recessed relative to the radially outermost portion of the post.