L-2--that's pretty cool, I took a look at what they have and I would highly recommend going with the
fore end integrated option as opposed to putting a rail attachment on. Firing a hefty recoiling shotshell while holding the foreend with your hand up against a rail attachment can bite you.
On second thought--L-2's suggestion is probably the better option cause it stays static with the magazine tube holder rather than going along for the ride when racking another shell.
Never mind!