Does anyone know how ammunition factories roll crimped their shotgun shells back in the day? Surely not the same way we reloaders do.

Joe, I too would like to know how they did it, there must be some photos somewhere. I have the old roll crimpers in 10, 12 and 16, they do a great job, better in fact than the ones you use in a drill press or hand drill, faster too.

Interesting 1885 review of the The Chamberlin Automatic Cartridge Loader (invented in 1883), but unfortunately details regarding the roll crimp are missing
https://cdnc.ucr.edu/?a=d&d=PRP18851024.2.35&e=-------en--20--1--txt-txIN--------1

Some factory Loads are still roll crimped. Presumably they use a similar set up as when applying the final crimp after folding in the case end for a star crimp?

Joe,
if you look back to AaronN 's post about James Erskine patents I think that there is a picture ( E ) of a commercial RTO machine: also if you search online you will find a Gunmaker's type of RTO as manufactured by Lightwood&Sons - a treadle operated model. I would hazard a guess that Factory versions were powered by belt drive from a power shaft linked to several Lightwood machines which were manually (sic) operated - I think that there were large numbers of female employees in the munitions & cartridge manufacturer industry at that period.