Bulk Smokeless powder was in widespread use after about 1895 in the U.S.; Dense Smokeless shortly thereafter.
Pressures of turn-of-the-century loads are here
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/preview

The Remington Model of 1894 Hammerless Grade “F.E.” Trap Gun was introduced in 1906 with decarbonized steel barrels; similar to Marlin “Special Rolled Steel” and Winchester “Rolled Steel”. Certainly no Live Bird or Inanimate Target competitor was using black powder in 1906.

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