I came across this picture yesterday showing cross-sections of different rails, and helped me out a lot with my admittedly-chronic hemming and hawing to figure out what direction I want to go for my builds.
What I’m wondering is this: does anyone have any more? Especially more popular ones like the Centurion rails, KAC URX, Troy series, Noveske NSR, and so on - the dimensions of the fore end dictate a lot, from basic ergonomics to what accessories can be mounted, and where.