One not talked about much...

The .401 GNR, .44 Magnum necked to .400" and loaded hot. Sort of a safer high pressure .38-40 WCF. I know some load .38-40 hot but oh my, if you accidentally stuck a full case load of H110, and a heavy LBT, in an old SA or new Service! I am subject to have an old antique so chambered gun around close, as well as other .38-40 guns that don't need THAT hot a load shot threw them. It makes lots of sense to me. Brass for a .44 Mag. is lots easier to source than .38-40 too!

The .401 shoots a 200 gr. at just under 1600 fps in my 6". I can go factory produced projectile weights from 155 to around 230 gr. It's a little brother to the .410 GNR on the .454. My second cylinder is .40 S&W. I was going to do 10mm but .40 brass is so cheap by comparison and I only have to seat the bullet long to load full 10mm loads.

One of my later and more radical contracted builds.