Did you take the choke out and make sure that it was a Rem turkey extra full? Because mine supposedly came with said choke, only when i took it out for cleaning before I shot it, I found that it was a modified choke. I was actually happy...was going to buy a jelly head anyway, but they were out of stock when I purchased the gun.

But, yes it is .687 if it is Rem turkey extra full. The Rem turkey super full's constriction is .665, but I would still go with something else. If you are ever interested in shooting with steel shot, neither of these will suffice.