Here's a nicely done throat impression sent in by a customer, from a Win 94 357 magnum.
The good news is that the throat is smooth and the angle is a gentle 5°, instead of the chattered 17° leade in my Marlin 1984.
The bad news is that the throat starts at case diameter, instead of stepping down to bullet diameter. I think it would be better if it stepped down to bullet diameter just in front of the case mouth, like a conventional rifle throat, but no one asked for my input.
The customer reports that 360 DW brass will almost, but not quite, chamber.