re: bore restrictions in the U.S.
1890 American Shooting Association Rules
https://archive.org/stream/fieldcovertrapsh01boga#page/458/mode/2up No limit on powder
In single bird (target) shooting the rise shall be:
Eighteen yards for ten-bore guns; limit 1 1/4 oz.
Sixteen yards for twelve-bore guns; limit 1 1/8 oz.
Fourteen yards for fourteen and sixteen bore guns; limit 1 oz.
Thirteen yards for twenty-bore guns; limit 7/8 oz.
In double-target shooting the rise shall be:
Sixteen yards for ten-bore guns.
Fourteen yards for twelve-bore guns.
Twelve yards for fourteen and sixteen bore guns.
Eleven yards for twenty-bore guns.
Rules for Live Bird Shooting - same load limitations
The rise shall be:
Thirty yards for ten-bore guns.
Twenty-eight yards for twelve-bore guns.
Twenty-six yards for fourteen and sixteen bore guns.
Twenty-five yards for twenty-bore guns.
Sporting Life April 5, 1890
https://digital.la84.org/digital/collection/p17103coll17/id/49988/rec/4 The 1898 “Trap Shooting Rules” by the American Shooting Association (courtesy of Randy Davis) listed the following rules:
Charge of powder was unlimited
Shot was limited to 1 1/4 oz. by “Dixon’s measure”
Weight limit (there was no weight limit in 1890 or 1893) and ‘naked’ was not stated:
10g - 9 lbs. 4 oz.
12g - 8 lbs. 4 oz.
16g - 7 lbs. 12 oz.
20g - 7 lbs. 8 oz.
Single target rise……….Double target rise:
10g - 18 yds….....……16 yds.
12g - 16 yds…...…....14 yds.
16g - 14 yds…...…....12 yds..
20g - 13 yds…...…....11 yds.