xyzzy45,
I’m not exactly sure what you mean by “Can I fit the M96 on a carbine-length 7" FF RAS and still be able to use the forend? Would a longer forend help”? If I follow you correctly, you are talking about placing the light in the six o’clock position, and still use the hand guard effectively for your hand, I would say no.
I originally had a short KAC FF RAS that I wanted to mount a Surefire L72 visible laser on my M4gery. This unit uses the same body and tail cap as the M95 series lights, which are shorter than the M96 series.
[img]http://photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=1193[/img]
As you can see in the photo below, this didn’t leave much room for a hand on the hand guard, and there would be even less with a M96 series.
[img]http://photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=1198[/img]
The alternative to this would be to move the light to either the three or nine o’clock position. While this is fine with a flashlight, this is not desirable with a laser because you don’t want the laser off axis from the barrel. My solution was to swap out the short RAS with a medium length KAC RAS. This allowed the laser to still be mounted in the six o’clock position and provide a place for my hand. See photo below.
[img]http://photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=1197[/img]
If you don’t need the light in the six o’clock position, you will probably be O.K., as long as you are running a vertical fore grip in the six o’clock position, so that you have something to wrap your hand around. Hope all this helps you to visulise your plans. If you have any questions, feel free to drop me a line.
Regards,
-Matthew