He stated that the monoblock was his preference because of the strength. I prefer the look of a clean monoblock by using the existing barrels (my preference). As far as the muzzle block Jim said that he is refining that. The Stoeger 405 Winchester that Jim built was for sale on Auction Arms a few months back and the muzzle block was huge thing. I have seen Ron Vella's doubles on the forums and he uses the existing barrels as the monoblock and it is clean.