Fox Collectors

Hi, This seems like a common topic, but I can't find anything in the search forum.
I purchased a late 20g AE gun this weekend. It was shipped in 1940.
The barrels a clearly marked 2 3/4" chambers. When measured ,they are definately 2 1/2" chambers. Does the marking on the barrel represent chamber length or shell size?
Thanks Dave

terc, if you use the brass Galazan gauge and measure an earlier 2 1/2 " Fox chamber you will not get much over 2 3/8" ! They left them short because of paper cases sealing better with slightly short chambers or so they thought! Bobby

Thanks for the input,
I did check the chamber length with two different types of gauges. The length is definately not more than 2 1/2". I will use 2 1/2" ammo when I use it. I just found it odd for the chambers to be so short in a 2 3/4" marked, late production Savage gun.
Thanks again,Dave