Thank you Brian. Do you have a way to measure the length of the forcing cones and choke constriction?

In response to a 1925 letter of inquiry, H.C. Carr of Hunter Arms returned a catalog and “The Wonder Gun” booklet describing the extraordinary merits of the Long Range Wild Fowl related to the “special long tapering choke” which enables “kills consistently at 80 yards” with “a good 70% pattern with field loads”.
2 3/4” Super X loads in a 3” gun were noted to cause “about 5% loss of pattern”. 32 inch barrels were suggested “because of the decided advantage in alignment for close, long range shooting” but 30” barrels were also offered.
“The Wonder Gun” booklet claimed full choke patterns in a 30” circle using a 3” shell and No. 4 shot (188 pellets) of 92% at 40 yards, 45.2% at 60 yards, and 29.2% at 70 yards.

Bro David found this in his 1926 LRWF:
Chambers measure 2 15/16” long. Right barrel forcing cone starts at 2 7/8” and goes to 4 5/8” then to bore. Left barrel forcing cone starts at 2 15/16” and goes to 4 7/8” then to bore.
Right barrel bore .7305 to 28 5/8” then tapers to choke constriction of .042 (.688) with no parallel area of choke; taper 3 3/8" from .730 to .688.
Left barrel bore .7305 to 29” then tapers to choke constriction of .042 (.688) with a parallel area 3/4” long; taper 2 1/4" long to start of 3/4" parallel of .688.

1924 ad "longer tapering choke"