The 1913 and 1914 A.H. Fox Gun Co. catalogues state 12-gauge guns are regularly chambered for 2 3/4" shells, 16-gauge 2 9/16" shells and 20-gauge 2 1/2" shells.
However, virtually every 12-gauge Ansley H. Fox gun made in Philadelphia (other than the HE-Grade Super-Fox) that I've run a chamber gauge in measures about 2 5/8". The chambers of unmolested 16-gauge guns run about 2 7/16" and 20-gauge guns a hair over 2 3/8". A very few graded guns were ordered with longer chambers.
Parker also cut the chambers slightly short for the roll-crimped shells of the era.
Drew's post is absolutely correct, we used paper shells or RST & Poly 2 1/2" shells under 1200 FPS in our old Sterlingworth double guns, or we rolled our own 2 1/2" shells, the paper 2 1/2" shells work real well. The guns were engineered for paper shells, not the modern Nitro type shells. The guns will last a long long time when fed the correct shells.
I believe BBK's point is that things change in the > 100 year life of a shotgun, sometimes by "inexpert" smiths
There is an easy way to measure shotgun chamber length using a 3" x 5" index card, rolled lengthwise, and slid into the chamber. It will partially unroll and expand to the chamber diameter. Gently advance the card until it stops at the end of the chamber (where the forcing cone constriction starts), use a pencil to mark the card at the breech end of the barrel, and repeat the steps to see if it always comes to same spot. Then use a ruler to measure the length marked on the card.
The chamber must be clean, and it works best with a new 3” X 5” card.
Exactly. You have no idea what has happened with the gun in the last 100yrs. Youll just buy a couple bricks of cerrosafe, a lead melting ladle, and some cork wads. Remove the ejectors/extractors and drive a couple wads down the barrel from the chamber until you feel them go past the chamber and into the barrel an inch or two. Then you melt the metal with a propane torch in the ladle and pour right in the chambers. It takes about 3 minutes to fully harden, then drive the wads and cast out from the muzzle end with a hard cleaning rod or dowel.
You can now measure the chambers and inspect to see if anyone has tried to lengthen it in the past.
Tony at CSMC sells a very nice Chamber gauge measuring tool, made of solid Brass, I purchased one a long time ago, they work perfectly. I measure every guns Chamber length to make sure I am using the correct shells in my Classic American double guns. Many sellers have no idea what the Chamber length of their guns really happens to be. Always measure your Chamber length to make sure what size shells should be used in your particular gun, before using the gun.
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