Just to support my contention that this issue (chamber length) is "confusing" -- check the article I linked to. The caption under the photo of the chamber length gauge reads: "As this simple chamber gauge shows, the chamber on this gun is short by today’s standards. If a 2 3/4-inch shell is fired in this chamber, the shell will open into the forcing cone, causing high pressure and damage to the shot column. The result will be excessive recoil and poor patterns."
That's the common misconception -- probably promoted by lawsuit phobia. As Scott Chapman noted in post #31 in this thread:
The google document that I posted was previously posted by Drew Hause back in April of this year. He wrote:
"Major Sir Gerald Burrard, The Modern Shotgun, Volume II, “The Cartridge”, 1955 3rd Revised Edition, p. 154 in reference to modern “star” crimped paper cases
“For all practical purposes any increase in pressure due to the longer cartridge case really does not exist provided the correct powder and shot charges for a nominal 2 1/2 inch cartridge are used.”
Obviously this applies to 2 3/4" hulls in 2 5/8" 12g chambers.
A summary of Bell's and Armbrust's study “Long Shells in Short Chambers”, in “Finding Out for Myself” Part V, Double Gun Journal, Winter 2001 is about 1/3 down here
https://docs.google.com/document/d/1...vwLYc-kGA/edit
The pressure increase for one load was 1200 psi
Threaded Mode