On a Stevens 311 20 gauge side by is there way to tell if the chokes are full or modified?

The easiest way to tell if your Stevens 311 20 gauge side-by-side shotgun has full or modified chokes is to look for the choke designation stamped on the barrel. The choke designation will be located near the muzzle of the barrel, and it will typically be stamped with the letter "F" for full or "M" for modified.

If there is no choke designation stamped on the barrel, you can also check the choke by measuring the diameter of the barrel at the muzzle. A full choke will have a diameter of .615 inches, while a modified choke will have a diameter of .625 inches.

If you are still not sure what choke your shotgun has, you can contact the manufacturer for assistance. They will be able to tell you the choke designation for your shotgun based on the serial number.