Let's use the right name- STOCK (just makes it easier to find on the computer)
First, need to know the make and model of your 12 gauge- this is not a one size fits all. You can check with a local gun dealer, and you can also check at gunpartscorp.com. They carry many parts for older firearms.
12
12 gauge the higher the gauge the thicker the item is
12 gauge is thicker than 14 gauge.
12 gauge is thicker than 20 gauge. The lower the gauge, the thicker the sheet metal or wire.
12 gauge by far
The 12-gauge is thicker.
Some are 12 gauge, some are 16 gauge. The MX16 is a 12 gauge frame; same frame size for both gauges.
12 gauge Springfield Arms 1916
12 gauge
No
The term 12 gauge is used to describe the caliber(bore diameter)of your shotgun.A 12 gauge barrel is 72 caliber,but the word gauge is used so people can determine you are talking about a shotgun,instead of a rifle.
12 has a bigger bore.