I grew up shooting these.
IMO, the 1100 was the first reliable semi-automatic shotgun.
They are a natural fit for many shooters....in a safe manner, with an empty chamber and magazine, close your eyes and mount the gun.
Now open your eyes, and note what you see....with a field stock and standard length of pull, I'm pretty much dead on.

It seems that you have a 28" Full Choke either plain barrel or ventilated rib...you didn't say. A vent rib is nice but a plain barrel works, too.
Measure from the end of the receiver to the muzzle.

That would be a good chukar, duck or pheasant gun. It would also be fun at the trap range....in fact the 1100 is legendary amongst the trap shooting community.

The current model is called 11-87