Take it to a gunsmith for verification
Your shotgun was made for Sears by Stevens, and is their model 311. It should take 2.5 inch and 3 inch .410 shells.
The Mossberg 500 shotgun typically takes 12-gauge shells, but it is also available in other gauges, such as 20-gauge and .410 bore. The shotgun can accommodate both standard-length shells (2.75 inches) and longer shells (3 inches) in the 12-gauge version. Always refer to the manufacturer's specifications for your specific model to ensure compatibility.
The Western Field model 30 pump action shotgun and the Stevens model 520 shotgun are one and the same firearm.Savage/Stevens made these for Montgomery Wards.The shotgun in question should show that it was chambered for the 12 gauge shotshell.The length of these shotgun shells were 2 3/4in. If your shotgun is not marked,I would have a gunsmith make a quick check of the chambering for you.This will only take a couple of minutes to do.
No. The 2 3/4 means Two and Three Quarters Inch shells (or shorter).
3/8 x 33.1"
Ensure you look at the stamped shell gauge on the side of the receiver (12 or 20 Gauge). Should be able to take 2 3/4" and 3" shells.
Peanut shells can take up to two years to decompose in the environment.
Your western field shotgun should take standard size 2 3/4in.shells in 16 gauge.However be aware that 16 gauge shotguns were chambered in 2 9/16in chambers until the 1920,s.If you have any doubt I would have a pro.gunsmith check the chamber to be sure of it,s length.
Peanut shells can take up to two years to decompose fully, depending on environmental conditions.
Take it to a gunsmith for exact measurement
K frame