Nope, not the same at all, as Klembo said.
The 1100 is a gas operated recoil system, and the 11-48 is long recoil action system.
The 11-48 barrel is designed to lock to the bolt and the entire bolt and barrel recoil together, identical to the Browning Auto 5 design.
An 11-48 will fit a Model 48, guaranteed (just checked this at the LGS a few days ago). They may fit an A-5, or vice versa, but there may be some differences between the two.
11-87 barrels will not interchange with the 1100, either, despite being based on the 1100 and using a similar gas system.