One thing to remember is that one generally doesn't want to mix petroleum based lubes with gunpowders...it kind of ruins things. Of course, I would hope that no one used so much lube that it dripped into the powder or brass.

For what it's worth: My understanding is that 3 in 1 used to be vegetable-oil-based that broke down easily in wet or hot environments. I don't know what the current formulation is. I believe now there are several lubricants sold under that brand name.

Another thing to consider for a dry lubricant would be wax or paraffin. Food grade paraffin (for my British empire friends, I am not talking about what we Yanks call Kerosene, which is what you blokes call paraffin) is easily available in blocks at grocery stores and you can rub it on the main metal ram.

You could also melt some, add just a bit of moly powder, and then let it harden...it would be an ideal dry lubricant for a lot of things, to include a reloading press.

It is sometimes used for bicycle chain lube because it does not pick up dust and dirt as much as liquid lubricants. Old candles would work as well. A thin layer of shoe wax or paste wax would also probably be effective.

Cheers.