As originally introduced the choices were very limited --
1913 Trojan Grade flyer.jpeg
12-gauge 30-inch full & full, or 12-, 16- or 20-gauge 28-inch modified & full.
By the 1922 Parker Bros. catalog the option of 26-inch barrels was added and "standard" borings were still 12-gauge 30-inch full & full, or 12-, 16- or 20-gauge 26- or 28-inch modified & full. And, the line "Barrels will be bored as above unless otherwise ordered." That is how things remained through the last Remington era catalog to include the Trojan Grade.
Threaded Mode