hmmm, logically thinking the bolt itself will be different of course, since its no longer of use with the new open bolt design. The brass tube will disappear thus leaving room for a open bolt design like in the G39.
The bolt carrier, dunno about that....could be that they keep it, could be that it will be a different design specific for the bolt.
As long as the Scar doesnt lose its distinctive *KLING* sound, its good for me
Its all assumption
About the barrel and hop up.
Imo, it should be possible to change the big metal block that holds the barrel without changing the whole upper receiver.
Something like the design of the G36, but molded a bit different to fit the Scars upper receiver.
Can't wait for this kit to come out, so I can put a long 6.01mm inner barrel in it, like I did with my G39, so it will shoot hard