UPDATE - I got the barrels off without removing any screws.
With my OU shotgun, pushing the lever over far enough to open the action was enough to remove the barrels if the fore arm was removed.
In the case of my new 20ga, I had to push the lever about a quarter of an inch farther (once the action was open) to disengage the pin holding the barrels in.
I'm just glad I didn't take it to a gunsmith to find this out.
Thanks to everyone for their input.