WS-1 is not jug choked - it is pretty much the exact opposite. Jug choking involves "enlarging the bore for a short length just behind the muzzle. The shot column expands into this area and is then constricted again at the muzzle." (PGCA) WS-1 involves constriction back from the muzzle followed by an enlarged diameter to muzzle. That terminal flare is of even greater diameter than the bore, hence the wall thickness concern. Whether the loss of wall thickness at muzzle is a concern at all depends on the individual. I'm not especially lucky, but have never damaged a WS-1 muzzle.
Most WS-1 12 ga chokes I've measured had 8-9 thou constriction. That, and decent 1.125 oz Pb, is good enough for most field situations. For NSCA I'd much rather have WS-2......well, more than that. But many small clubs set courses for which IC would be adequate.
