3" Magnum determination

gregw

A friends husband had recently passed away leaving her his firearms. One shotgun in particular he had 're chambered for 3" from 2 3/4. The dilemma is this. The gunsmith is no longer in business and she can't locate him. The gun is not stamped with any 3" markings so she does not know which one it is. is there any way to tell the barrels are 3" if there are no markings

charliemeyer007

Yes. It will need to be accurately measured. A loaded 3" will often fit in a 2.75" chamber, the issue is what/where the crimp unfolds into. You can try a fired 3" empty, if it chambers easily then it a good bet its the 3" one. If it some old on the loose side double then the fired case could drag on both chambers.

babun

Any decent machine shop can measure it for you. doesn't need to be a gunsmith.
Look at this page about chamber lengths, show it to the machinist.
he can then determine how much was cut from the forcing cone to make the chamber longer.

http://www.gunnersden.com/index.htm.shotguns.html

Laredo Lefty

All modern shotguns are stamped with the shell sizes the barrels are supposed to accept. Just because you can fit a shell into the chamber does not mean its safe to shoot.

If there are "NO markings" it might be a very old gun not safe with any modern smokeless powder ammo. If the barrel is not marked I would stay with 2 3/4" ammo.

pip5255

if the gunsmith didn't finish the job by remarking barrel then it may not have been tested either so it is what is stamped on barrel or if unmarked it may not even accept 2 3/4" shells. have it checked by competent gunsmith and remarked as such.