without the roller bearing it's a 1/8 in. disc of nylatron , it works almost as good as the roller bearing.
The .20 shadow is very accurate, groups 1 inch at 50 yards with FTS's. It's my favorite long range rifle for tree rats, knocks them out of the trees with real authority.
The .20 will get better and better as you shoot it, at least mine has.
I just got a new Shadow today and thinking about making another .20 out of it.