I read what you wrote about this on another forum. You said you desiged it to allow for long range bench shooting. The added weight to help stabilize the gun and recoil. I cant remember what you said it weighed but I remember it is HEAVY. How hot did the barrel get under the "Box". I am guessing pretty damn hot!
Believe it or not the heat buildup in the compartment was very marginal. A few mag dumps of .308 got the bull barrel hot enough to melt your face (OK - that's a bit far fetched, but you get the idea). Because of the venting though the heat dispatched into the atmosphere very quickly and build up was almost non-existent.
Revision 1 begins next week, so hopefully it will be done by the start/middle of Feb.
Revisions will include:
JP Muzzle Brake fully integrated. The tip of the brake will sit flush with the shroud and appropriate vents will be cut to allow proper exit of gas. (Think of the exhaust design of newer sports cars - the muzzle tips all look integrated to the chassis).
VLTOR side mounted bi-pod legs. We did experience some "wobble" do to weight/height with a standard bi-pod. Putting side mounts will eliminate the tipsy feel and also lower the center of gravity a bit more.
The shroud itself will be getting its overall shape trimmed up a bit. Moving toward a classic octo-shape, but still retain its over sized dimensions for the weight compartments (I think we are shaving 1/2" off the height and 1/2" of the width, but length remains the same). The shroud will flow better with the rifles lines than it does currently.
Other goodies include an upgraded 1 piece quick detach scope mount, a phase 5 extended bolt release, extended mag release, better buffer tube setup and some bolt carrier upgrades.
Weight fully loaded with all gear present puts it at about 27lbs 5o, our overall goal was somewhere in the 30-40lb area.
The great thing about all this is its all modular and the rifle can be stripped back to it standard form in a minute or two.