You'll be hard pressed to find many 6.8 in a 10.5". I know Wilson Combat has a SBR rifle with 11.3" barrel. Noveske makes a 6.8 short barrel but not sure what chamber it is, just says MOD 1 match chamber. Plus the twist is an 12 which I feel isn't enough in a short barrel.
_________________________ 07 FFL firstname.lastname@example.org 214-945-5520 The 6.8 is the #1 choice for hunting deer and hogs in an AR15
I bought a complete SBR upper from Aero. Seems like a nice unit for the $. I have an Aimpoint on it so can't say how accurate it, don't really care much at the ranges it's used for anyhow. I'd buy one again.
I second Blackstone Arms for 6.8.... given at some point you realize that 12.5" is a lot more realistic.