I have two Winchester 1300 Defenders that I keep as bump-in-the-night guns, each with a Fivemega 6P body, Z59 tailcap, and either a Malkoff P7 or P60F lamp module. Light mount is CDMGear MOD-C clamp which has steel thread inserts for long life of the threads. Awesome quality and a good price.
I love this set up because it's simple, lightweight, lean and trim (no wires or remote switches needed either) and the lights can also be used as flashlights when desired. And I can use whatever lamp module is appropriate for the application. Mine are used only for civilian home defense, so the lamps are wide and floody. I have no need for throw with HD shotguns. With the Z59 tailcap, momentary is easy to use as is constant on, while my hand is on the forearm of the shotgun.
For a much less expensive approach (Malkoffs, Z59's etc. aren't cheap), this same MOC-C clamp will hold a Streamlight Polytac flashlight; that's about $45 for the light and about $55 for the MOD-C clamp. Around $100 for an outstanding and very simple shotgun light. Sweet.
Great choice in shotguns, by the way... while I have and enjoy Mossberg 500, 590, and Remington 870Police shotguns, the Winchester 1300 Defender is unique in having such a high capacity (8-shots) with just an 18" barrel. And NO extensions to fool around with as they have a one-piece, full-length mag tube. Sweet!
