CZ, as you know, the damage to tighter chokes with steel (and even lead) occurs when incompressible large shot, "bridges" and rings (or worse) the restricted area. I have shot small htl for a while and not noted any scratches, etc., after taking the precautions of wrap/htl wads. That doesn't mean it won't happen, but so far, so good. Good to know that mylar alone offers sufficient protection of your guns. The advice often given if one is concerned about potential scratches in a gun's barrel, then don't shoot anything but lead. Gil
