Winchester model 12 - 12gauge chamber lengths

[Chuck3436]

Just picked one up off the EE. Beautiful 1926 riot gun model.

Lots of misinformation out there...are they ALL chambered for 2 3/4" or are some chambered for 2 5/8", 2.5"!?

I quote some sources I found that claim all 12 gauge models can handle 2 3/4" shells.

Winchester Shotguns, by Dennis Adler, page 70 and History of Winchester Firearms 1866-1980, by Duncan Barnes et al, page 70, both state that the 12 gauge Model 12 came with 2 3/4" chambers.

The Winchester Book, by George Madis, page 537 explains that the introduction of the 3" chambered Heavy Duck Gun necessitated the chamber length markings in order to inform the buyer of the proper ammunition for his shotgun.

Before the introduction of the 3" magnum shell, American made 12 gauge ammunition was 2 3/4" only. Shorter versions were available in Europe, but they would fire safely in the longer American chamber, Thus, there was no necessity to mark the barrels as to chamber length prior to the introduction of the magnum shell.

The 12 gauge Model 12 has always had a chamber at least 2 3/4" long.

Read more: http://www.shotgunworld.com/bbs/viewtopic.php?f=2&t=266415&start=40#ixzz1gT7wnmyW

I have also seen alot of people who claim gunsmiths have measured them as well as wikipedia that claims that 12 gauge models made before 1927 have the shorter chamber.

I want to keep this shotgun, but I want to make sure its safe to shoot. From my readings, measuring the chamber is a little finicky with these shotguns as well, leading to alot of misinformation.

What are your thoughts?