I have a 16 gauge 31 with a 27" barrel. The choke is marked Mod, and there is .013 constriction.
Does anyone know what barrel lengths were offered on the 31? I see plenty of 28" barrels out there, but mine is 27" measured from the front of the receiver. Hmmm?
Model 31 barrel lengths?
Re: Model 31 barrel lengths?
That is probably a Remington 28". Remington's barrels usually are not an exact inch measurement when you measure them the correct way; from the closed breech face to the end of the barrel, inside the barrel. That is one of the secrets of why they feel so good. 

What could have happened... did.
Re: Model 31 barrel lengths?
I also have a Model 31 16 gauge with a modified choke and 28 inch barrel. From the end of the receiver to the tip of the muzzle it measures 27 1/8 inches. I am sure those other 7/8 inch are in the receiver. Why the question in the first place?
300 Savage
300 Savage