Canning book that came with All American canner has a section on canning using actual cans. You buy the cans, the lids, a sealer. Fill em, seal em, hit em in the canner?

How does this work? Why don't the cans blow up? They can't vent like a jar lid does.

Just a pasturization process?

They are cooked under pressure. I do fish that way. Important to make sure the sealer is adjusted right.

I would become morman, they have all the cool stuff to do it

When canning with glass jars and lids, the contents of the jar are also under pressure, and at some point along the way the two equalize, but before that the expanding liquid in the jar must vent steam or air so when it cools down, the lid seals and since volume of contents is now less than when it started, a vacuum is pulled as contents cool down.

I've read where a finished tin can lid will also pull in, but if that is so, it would have had to vent too? How does that work?

I believe a small amount of vapor is forced out the can lid seal, because after canning my water has a bit of cooked fish smell

Folks in Newfoundland can moose in metal cans. A couple people in town own canners, and they share.

Cons-Metal cans are not reusable and here they cost about 1.35 for talls w lid. Sealer also extra expense. Can’t see your product. Pros-Easier to ship, lighter, not fragile like glass.

The Mormons let everybody use their canning equipment.

http://prepared-housewives.com/lds-cannery-locations-questions-answers/#:~:text=The%20Home%20Storage%20Centers%20(aka,families%20become%20more%20self%2Dreliant.

Keith