I came across this interesting animation of how the Browning Auto-5 shotgun works. It would also show how the Remington Model 11 and Savage 720/745 shotguns work. Interestingly, there were two Japanese made clones of the Auto-5 that were introduced in the 1970s: the Auto Pointer by Yamamoto of Tokyo and Herter’s SL-18.
I have a FN labeled Auto-5 in 16 gauge that was my father-in-law’s. I think he picked it up at an auction minus its stock. One of these days I’m going to get it restocked.