The history and science of short chambers

[Drew Hause]

Not everyone is convinced that bore size or forcing cone length matters; including Neil Winston
https://www.trapshooters.com/threads....365553/page-4

Neil Winston “Have Today's Increased Bore Sizes Improved Trap Gun Performance?” 2016
https://web.archive.org/web/20180829...e_Diameter.pdf

And for a historical perspective, the chamberless Tolley "Altro" was introduced in the mid-1890s
https://books.google.com/books?id=BF...AJ&pg=PA31&lpg
https://books.google.com/books?id=Bz...AJ&pg=PT92&lpg

Dr. Charles J. Heath chamberless patent
Forest & Stream July 1921
https://books.google.com/books?id=x1...J&pg=PA308&lpg

1922
Sporting Firearms of Today in Use
https://books.google.com/books?id=9X...AJ&pg=PA95&lpg

Field & Stream, August 1922
https://books.google.com/books?id=XQ...J&pg=PA470&lpg

A few Lefever have been documented with "Taper System of Boring"; gradual constriction from end of chamber to the muzzle.
Forest & Stream 1909 "First to adopt the taper choke system."
https://books.google.com/books?id=l0...J&pg=PA395&lpg

Charles Askins on "taper choke" in October 1917 "Recreation"
https://books.google.com/books?id=gX...=RA1-PA210&lpg



Daryl Hallquist has confirmed that an occasional Lefever 12 gauge has bores tapering from the breech to the muzzle (.756 to .708 left and .715 right on one gun). Most have a standard U.S. .729 - .732" parallel bore.

[Drew Hause]

Actual performance testing as opposed to marketing hyperbole

Jim Eyster 2010
http://www.jimeyster.com/testing/doc...one%20Test.pdf

Matt (discusses increased volume post-cone lengthening)
https://www.trapshooters.com/threads.../#post-8585555

[Drew Hause]

Sporting Guns and Gunpowders: Comprising a Selection from Reports of Experiments, and Other Articles Published in the “Field” Newspaper, Relative to Firearms and Explosives, Volumes 1-2, 1897, “The Junction of the Chamber and the Bore”
https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA303