That must be a typo, as it's a factory part, and even the picture shows 6 charge holes. I'd be willing to wager that if you called the tomorrow, they could confirm it; they also list the factory part number, if you wanted to check with S&W. It specifically says it's for a 631 and a 631LS, both of which are 6 shot cylinders.

(they probably just copied the verbiage from the Model 60 description....)

Added: Midway shows it at the same price but is a special order, with a date of 4/29/17 if ordered today.

• Product #: 444985, with the same S&W part # as Brownell's

RWJ