Right now my carbine has a Troy 12in FSP rail, great piece but it's far more rail than I use.   Essentially I want to chop my FSB and go with a folding front rail mounted sight to match the folding Troy I already have.   I'm liking the Centurion 10in rail but is 10in good for a light and vfg?    My ninja search skills didn't reveal many 10in rail carbine pics but the one I saw looks like the gas block is at least partially exposed.   The 11in would cover it I think but honestly if I was going 11in might as well get another 12 which is more than I need anyway.   Any thoughts from folks with either 10in or 11in rails?    I have a 16in barrel.

IMO 10" is too short.  12 is perfect for 16-18" barrels.

This is 10"

The 11 inch has 1 more than the 10.

12 inch M.I. rail on a 16 inch carbine barrel.