[Austin W Hogan]

Here is another old figure from the disc cleanup. It shows serial numbers and Parker events vs calendar year from Charlie's Serialization, TSP and other sources. The reason supporting 80% of Parkers being made for loads much lighter than the modern day is that s/n 200000 appears in the early 1920's at least 5 years prior to Super X and Remington Express.
By 1930 factory 16 and 20 ga loads exceeded the 10 gauge loads, and 12 gauge loads exceeded the ten gauge and approached the 8 gauge of 1900. The production graph shoes 50% of Parkers were made before 1900. The only steady plodder was the 2 3/4 or 3 dram 1 1/8 ounce twelve ga load.
Incidentally dram equivalent is not a complex concept; it is a load that produces the same speed as that amount of black powder behind the same shot charge.

Best, Austin