The 270 supermag or maybe better known as the 270 Maximum is a 357 Maximum case necked down to 277. It hold about 21 grains of 2015, and shoots a 140 bullet exceptionally well. The case capacity puts it on par with a 222 necked up to 270, but with a rimmed case for good extraction from a TC handgun. Recoil is tolerable, I have a muzzlebrake on my handgun that lets me shoot it with a 12x riflescope.
Just browsing this site. May come back.