[Researcher]

The "normal" American 8-gauge guns were chambered for 3 1/4 inch shells, and virtually all factory loaded 8-gauge shells were 3 1/4 inch. Union Metallic Cartridge Co. offered 8-gauge NPEs in lengths to 4-inch and a few Parker Bros. 8-gauges were so chambered.

From the 1900 Union Metallic Cartridge Co. catalog --

8-gauge TRAP Shells 1900.png

1901 --

8-gauge TRAP Shells 1901.png

1903 --

1903 UMC 8-gauge Loads.jpeg

1905 --

8-Gauge Trap Shells 1905.png

June 1909 --

8-Gauge ARROW Shells loaded with Bulk Smokeless June 1909.png