I was visiting with an old scrounger today and bought an old 12 guage shotshell loading block. 2-1/2" brass hulls and plastic hulls trimmed and sized will slide into the "chambers". The hole above is smaller diameter and the very top has a radius. The top block indexes on the pegs in the bottom part.

There is just the remnant of a paper sticker and no other markings to who may have made or used it. My wife thinks it's home made. I don't think so. It is of tool maker quality and precisely made. I can see it used in an assembly line with people working at stations filling and stuffing components. Maybe they would have powder and shot dispensers that would drop 50 at a time?

Anyone see anything like this? Know anything about it?

I have one of the Erskine reloading machines in 20 bore, both regular shells and pinfire capable. Does 100 at a time. Different boards for different grains of Schultz powder and same for shot. https://paulcollis.dphoto.com/#/album/ec2b5l

The Bridgeport Gun Implement Company made those. The ramming/seating device had five plungers on a handle designed to be used with both hands. The block should be marked with a stamp showing 'B.G.I' with a number beneath it.

Cornell Pubs has several Bridgeport Reloading catalogs
https://www.cornellpubs.com/old-guns/historic-bridgeport.php

I took it out in the bright sunlight and looked it over closely but didn't find a B.G.I. stamp anywhere.

The crimp roller is marked B.G.I. I've had it and other old loading tools a long time.

I did a Google search for a B.G.I. box (and other combinations) but didn't come up with anything looking like this.

Cool! Now THIS is a double gun thread!