- The NcSTAR Shotgun Magazine Tube Rail Mount is designed to fit onto most 1" diameter extended shotgun magazines tubes. When mounted onto your shotgun extended magazine tube, this will allow you to attach multiple weaver and Picatinny style accessories to your shotgun. The rails are designed so that you can attach your accessories like lasers and flashlight at any of the 5 angles that the rails provide. Not only can you mount your accessories at the typical 3, 6, and 9 O'clock positions; you can also mount the accessories in the 4/5 and 7/8 O'clock positions. This can also be used on any 1" diameter accessories like 1" scope tube bodies, flashlights, and lasers. Mounts onto magazine tube with the two provided Allen head bolts. Installation may require user to disassemble shotgun barrel, magazine tube/end cap/clamp.