A little known secret here, that this "embarrassed" Moderator just recently found out about.
Vendor Sponsor MannyCA makes a tool similar to a gas check maker, which is designed to form percussion caps from Aluminum beverage cans.
http://castboolits.gunloads.com/show...ready-for-sale
I ordered one a while back, and it arrived yesterday. It is nicely machined and threaded to fit on top of a reloading press (for stability) and also came with a threaded base, so I could use this at the range as well. Within 5 minutes of opening the package and cleaning up and cutting a aluminum can...I had several caps easily made. The crimp/crease forming of the sides, makes for a fairly thick sided and sturdy cap. It fit nice and snug on my Ruger Old army, with the original nipples. Not much else to say about it...til I get some capgun caps and try these out...mostly I am wondering if the cap stays on the revolver's nipples throughout firing all the chambers.
and now for pictures...