Serial number 395820 would be a 1925 vintage Flues. There was no such thing as 2 3/4 inch 28-gauge shells from our North American ammunition manufacturers at that time. The "standard" 28-gauge shell from the get go was a 2 1/2 inch shell which carried a load of 5/8 ounce of shot pushed by 1 3/4 drams of bulk smokeless powder or the equivalent of dense smokeless powder. Our manufacturers offered a 2 7/8 inch NPE, and from time to time the longer 28-gauge shell was offered with 2 drams pushing the same 5/8 ounce of shot a bit faster. The 3/4 ounce 28-gauge Super-X load with progressive burning smokeless powder first appears in the March 1, 1931,
Western Ammunition for Rifle, Revolver and Shotgun, put up in their 2 7/8 inch FIELD shell.
Just before WW-II our manufacturers began offering their 28-gauge Skeet loads in a 2 3/4 inch case and right after WW-II, the 28-gauge was standardized at 2 3/4 inch in North America.
All the above said, back before The Great War, Chas. Askins was writing about hand loading up to 2 1/8 drams of bulk smokeless powder and 3/4 ounce of shot in the 28-gauge 2 7/8 inch hulls for use in his 6 3/4 pound 30-inch barrel Parker Bros.
My own 1915-vintage Flues 30-inch barrel 28-gauge has 2 7/8 inch chambers and only weighs a fraction of an ounce over five pounds. While it probably digested some Super-X type loads back in the day, for what little I shoot it, I stick to the 2 1/2 inch, 5/8 ounce RSTs.
