Hello All, I am looking to replace the forend on my 500, however I am finding it difficult to get information regarding the slide tube. My Mossberg has a 5 round Magazine (holds up to 5, 3" shells). The forend it came with does not have the Action Slide tube assembly built into the forend, like other models I have seen. It appears to be plastic all the way around the Mag. The slide arms are attached directly to the forend. (based on the research I've done for this particular issue, this is the way the Post 2006 Mossberg 500's are). I am in the process of purchasing a whole new forend set, including a full action slid assembly, but am not sure what size Slide Assembly I need to purchase. Is the size of the Slide tube based of the capacity of my Magazine? Or is it based off the size of the forend? Are the Mag Size and Slide Tube Size related? Anyhow, that is my little issue. Hope I can get some help and thanks in advance!