I just purchased the barrel shroud after staring at it on my store wall for months. It fits my J&J like a glove and I'm not sure where the other guy bought his shroud but it should have come with several different inserts that friction fit the barrel to the shroud and allow something for the set screws to tighten to without any damage to the barrel.
As a matter of fact I am now recommending these to owners of the Stiffi barrels because they seem like they would fit great and be VERY protective leaving only the front few inches of the barrel exposed making it very hard to actually damage the carbon fiber (good thing).
I love the way it looks and instantly makes a rather plain looking Custom 98 look good enough that everyones worried about being shot by it.... (maybe its the 330 round cyclone with the r/t setup too?)
Great buy and bang for the buck. It looks good all around great fit that doesn't shift around like some shrouds do and it also doubles as a protector for your barrels if your picky about scratches like I am.