How to mesure the chamber on a shotty barrel?

[salt]

Hey guys I want to find out what the length of my chamber is on my shotty. Is there a simple way to do it. What is the total copasity that a 3 inch shell needs to fire. Thanks

 

[SDC]

The shell length is of a fired shell, so a shotgun needs a 3" chamber to safely fire a 3" shell. Brownells has a chamber-length gauge, but it's just a metal ruler (the width of a shell) that slides into the chamber until it hits the forcing cone, where you can read the length off of a scribed measurement. If this shotgun is at all modern, it should also be MARKED somewhere on it, maybe in millimetres; 2 3/4"=70mm, 3"=76mm.

 

[guntech]

I don't know about "shotty" barrels but most modern shotguns have 2 and 3/4 inch chambers if they are not marked otherwise. Older unmarked shotguns can be even shorter. The 3 inch and longer chambers are all indicated on the barrel.

You need a SHOTGUN chamber gauge to measure your chamber.

 

[marshall]

chamber gauge

I made one on my wood lathe, could turn
one on metal one if I had one.
I turned a piece of hard wood to fit snug
in the camber and then marked the length
on it from shot guns that I know what the
length of shell it was made for ie. 2 3/4
or 3" or 3 1/2" A cheap way to do it.

 

[sunray]

The ammo it takes should be marked on the barrel. If not, it's likely 2.75". The receiver on a 3" is a bit stouter as well.