remington 11A semi auto shotgun, don`t know what gauge it is

[rhall007]

It has RFP ON THE BARREL NEXT TO THE RECEIVER,SERIAL NUMBER IS 459XXX ANY INFO WOULD BE HELPFUL

[admin]

Model 11's have a different serial range for calibers this is a 12 gauge, it's also late enough (1921->) it will be date code stamped on the barrel.
Go to the main page and clicked the manufactured dates link and the details are there...