My bag doesn't quite fit in sideways, I have to have it in a little turned. If I remember correctly this was the same with my WJ. See the pic below, I tried to lighten it up but a black bag on top of the black interior taken at night makes it a tough picture.
Callaway Walk Bag
Callaway Big Bertha 460 Driver
Ping i5 Irons
All standard cut length if that helps with the sizing.