[Researcher01]

There were three (or 4) iterations of the Remington Model 31. The original 1931 version has a take-down mechanism on the end of the magazine tube like this that screws down and releases the barrel to twist off the receiver --

The 1934 version has a mechanism that just pushes down and turns a bit to the side releasing the barrel to twist off the receiver --

Some shop manuals describe a sub variant called the 1936 version.

The final version is the 1941 version that goes back to a screw down mechanism --

The 1941 version also has the larger trigger group for a better grip to trigger feel.

When the Model 31 was introduced the Model 31A "Standard" Grade had a checkered stock and slide handle --

The earliest Model 31 12-gauge guns had the magazine tube crimped to only allow three shells, but quickly the added the uncrimped 5-shot version with a magazine plug to reduce the gun to three shots for migratory waterfowl hunting.

The checkered stocks and slide handles continued through 1936. In 1937 Remington introduced the Model 31AP "Standard" Grade with a plain stock and a ringed slide handle --

and the guns with checkered wood became the Model 31AC "Standard" Grade --

By 1939 the guns with checkered stocks and slide handles must have been cleaned out of inventory and the gun with the plain stock and ringed forearm was the Model 31A "Standard" Grade. Up through about this time the very rare Model 31B "Special" Grade had a checkered stock and slide handle of imported walnut but for 1939 Remington introduced American Walnut on their B "Special Grades --

For 1941 they introduced the final version with the larger trigger group and also a lightweight version with an "Aeromet" receiver in 12-gauge --

Almost immediately the catalogs said the lightweight wasn't available due to material shortages. After WW-II the lightweight was offered in all three gauges. I think this is about the maximum number of photos I can post.

 

[Researcher01]

Is the 1941 version with the larger trigger group more desirable?

They are the most common and they are the ones I prefer, however, my only 16-gauge is the 1931 version.

Like the Winchester Model 12, the 16- and 20-gauge Model 31s are built on the same receiver. The 12-gauge Model 31s began with serial number 1 and I've recorded them into the 1265xx range with a July 1949 barrel date code. The 16- & 20-gauge were serial numbered beginning at 500000 and I've recorded them to the 5799xx range with a May 1949 barrel date code.

 

[Researcher01]

The problem of the tip breaking off the action bar on high volume use Model 31s is probably the main reason for the twin action bars on the Model 870. I wonder how many Model 31 "Target" Grades or Model 31 Skeet Guns still are on their original action bar? The action bar on my Model 31TC, which also has a skeet barrel, went while shooting the first round on the new Beomat Skeet Machines at the old Spokane Gun Club. At that time Numrich had new manufactured ones for 12-gauge guns.

I'm sure they last a couple of lifetimes in the average hunting or lightly used target gun.