Not to sound too flippant, but whenever a customer requested one. Even the late Remington era specification sheets shown on pages 164 to 169 of
The Parker Story show a 2 5/8 inch long chamber intended for 2 3/4 inch shells. I find the Parker hang tags I've managed to save pictures of somewhat confusing. Here is one from 1902 --
108998 12-gauge, 2 3-4 inch, 1 1-4 ounce.jpeg
What does it mean
Length of Shell 2 5/8 Inches and then
Use Shells 2 3/4 Long? This tag shows that the gun was targeted with a 1 1/4 ounce load. In those days one could get factory 1 1/4 ounce 12-gauge loads in a 2 5/8 inch shell. Between 1906 and 1907 our North American ammunition manufacturers quit offering 1 1/4 ounce 12-gauge loads in the 2 5/8 inch shell. From then on one needed to go to the 2 3/4 inch or longer 12-gauge shells for 1 1/4 ounce loads.
This 1920 vintage hang-tag shows this 12-gauge gun was targeted with a 1 1/8 ounce load and states
Use Shells 2 5/8 Long.
189153 12-gauge, 2 5-8 inch, 1 1-8 ounce.jpg
Wonder how many 2 3/4 inch shells 189153 has digested since 1920? Here is a similar tag from 1924 --
211184 12-gauge, 2 5-8 inch, 1 1-8 ounce.jpg
Here is a 1926 vintage hang-tag showing
Use Shells 2 3/4 Long and the gun is targeted with a 1 1/4 ounce load --
216599 12-gauge, 2 3-4 inch, 1 1-4 ounce.jpg
Finally here is an Ilion era hang-tag for a fairly light 12-gauge VH that states
Chambered for 2 3/4 inch shell.
240647 12-gauge, 2 3-4 inch.jpg