This is available online here
https://onlinebooks.library.upenn.ed...armsexplosives
https://dds.crl.edu/crldelivery/28565
There are allegedly some articles on experiments with Lincoln Jefferies BSA air-rifles and stuff if someone cares to dig though all the other late 19th C & early 20th C stuff.
Here is a patent for a breech lock to give a break-barrel a rigid & air-tight lock-up ...
https://dds.crl.edu/item/286812