Got a new M590 20", have a TLR1... Mesa mount or railed forend?

[scootle]

For my 590 I used the Surefire railed forearm. It has a VTAC light mount with a 6P barrel light (w/ LED head) and is activated by a pressure pad that attaches to the rail. VTAC mount is at 3 o'clock as mentioned by scootie for the same reason.

Something that was pointed out to me in a shotgun class is that you need to be careful with pressure-pad switches... esp on shotguns. A fellow student had a Surefire fore-end on his shotgun and every time he racked his slide he'd fire off a burst of white light in the process.

This may or may not be a liability -- and you can probably be trained to minimize the occurrence, but just keep this in mind. I for one, sort of prefer the configuration where the switch for my light is discrete and positioned such that it takes a defined movement on my part to trigger it on (or off).

[IZinterrogator]

The Surefire integral forends come with a switch-blocker plate for just that reason.