I'm looking for a black 10-12" completely round handguard w/keymod system with OUT a top rail. I've found in carbon fiber only - which I'm not interested for this build.

Any help getting me point in the right direction would be greatly appreciated.

SLR has the Solo Ultra Lite, but that's all I can think of.  It has only a small section of top rail to the front and isn't completely round.

I know these (http://cdn3.volusion.com/bosgt.mtuyr/v/vspfiles/photos/APCFSTD-1.jpg?1424783355) aren't keymod, and are carbon fiber, but are as round as I'm hoping for. I'm beginning to think all keymods are only semi round so the rails mount flush.

Key mod accessories need a flat base to be stable. If they had a matching rounded base to match a round tube it wouldn't be key mod because it wouldn't work across all key mod platforms.  I don't really get the point of key mod or m lock if all your going to do it attach rails and attach things to the rails. I can see where it would be an advantage if your accessories attach directly to the tube with out a rail sandwiched inbetween.

If your going to attach things to picatinny rails then I would go for a rounded tube and put sections of rail where you desire to have accessories attached.

A lot of mounts are coming around, now.  They're both still relatively new.  I never thought I would run a Keymod when they first appeared, but the cleaner, lighter, reduced-diameter rail had me sold when I first handled one.  I don't want to go any other route now.  Rails where you need them, nothing more.

I like the look & feel of a round handguard, and currently only plan to put a bipod on it, but – want to reserve the possibilty to change things around later. I used the rail comment as possible rational as to way I can’t find what I’m looking. I’m not an engineer, but seems to me - making a round tube with a keymode systems wouldn’t change anything across all key mod platforms, but only require a solid adapter to use it. The picatinny rail itself is nothing more than an adapter (much younger than the AR) that allows components with picatinny adapters on them to attach to it.

If what I want doesn’t exist – then so be it, but there was no harm in asking. Thanks for the information.

Not keymod, but these are comfortable, solid and great looking (IMO).

If they can make rails, even short ones, to fit these (http://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=450), they they can make rails, or any other component for that matter, to fit keymod handguards. I can't be the 1st to to wonder this, so that's why I figured it'd be reasonable to expect to find in production.

Those rails are proprietary.  The flat surface of KeyMod is part of the specification, just like the hole size, shape and spacing.  A round hand guard would not work properly with KeyMod accessories, as they are not countoured on the bottom like the ones you linked.  They are flat, per KeyMod spec.

http://upload.wikimedia.org/wikipedia/commons/2/2a/KeyMod_Technical_Drawings.pdf

The rail is made to a universal specification. The back side that is against the tube is not. Key mod is a universal attachment method so they simply cannot make a curved key mod attachment to match a round tube. The same reason why all picatinny rails have the same shape and spacing.

Look at the JP Rapid Configuration tube if you want a round tube. It's not key mod but you can attach a 2" section of rail on the underside of the tube. Then use a LaRue mount to attach an Atlas or Haris bi pod. It also doesn't have a top rail. One can be added later on down the road if you change your mind.