.445 Supermag cases, .410 shot cup trimmed to length, overshot wad cut from business card material, powder charge from Speer manual, fill the shot to near the top, add the overshot wad and add a small amount of caulk or RTV. Swaged down the front of the case a bit so they fit into the chamber throats; first time with a 7x57 sizer die, after the first firing I use a 10mm die on the "neck". I push the shoulder back enough to fit in .44 Special. You should be able to do similar for .45 with modified .444 Marlin brass and for .38 with .357 maximum brass. I'm pretty sure I got the idea from DocRocket.

[Linked Image from i.imgur.com]

I doubt they hold more than the Speer capsules pictured, but are less fragile.

Last edited by Son_of_the_Gael; 05/13/22.
'Four legs good, two legs baaaad."
----------------------------------------------
"Jimmy, some of it's magic,
Some of it's tragic,
But I had a good life all the way."
(Jimmy Buffett)

SotG