The patent for the Perrin revolver was granted on the 5th of October 1859 as opposed to the Galand Revolver which was launched in 1868. The rim thickness on the Perrin cartridge is also about 1/3rd thicker than the Galand cartridge. Below is a table with measurements of specimens by Aaron Newcomer from his website. (Erlmeier, Brandt Ref. 175).

The internal primers on all three these specimens are magnetic