I'm going to have to invest in a box... sounds like Winchester's version of the Remington Hevi-shot I'm shooting now.

A hunting buddy here has an 870 Super and shoots 3 1/2" Remington Hevi's, the 1 7/8 ounce payload of #6's through the factory .665 tube. Gets really great patterns out to 40. All guns shoot differently, but that makes the 3rd 870 Super I've seen locally that liked that particular combination.

I'm almost done playing around for this year, settling on the same shell as above fired out of a .660 non ported Hastings in my 3 1/2" Browning. I may just get a box of Winchester tonight yet... just for fun.