Ps. People, we all know the 270 Win isn’t short action. So why recommend it when the OP clearly stated that as a foundational requirement?
Because in the OP the .473 case head and 2800 to 3100 fps pushes the choices down to the .243 and .260,and the OP listed the .280 as an option.
Which tells me the short action criteria is not absolute.He said "preferred"
Life is all about tradeoffs and compromises.
Its also true that some rifles use the same receiver for long and short,they just block the mag.
If "short bolt throw" is the reason...I might consider that a cartridge like the 270 easily fulfills the rest of my criteria with one small compromise.
If bolt throw /follow upshot is the rationale...
Well,imagine this.You are in the woods,opening day.
In the distance,you hear "Boom" then silence. Likely story? Tag filled.
You hear another....Boom,then 5 or 10 secomds,and "boom" again. Likely story? Finished him.Filled tag.
You hear "Boom..boom...boom....boom..boom" Wow! All in 12 seconds! Rapid follow up shots. Likely story? Not good.
Its nice to have a follow up available.
But stroking a long action isn't the critical factor. Frankly,if short action is important,then compromise mag capacity for a WSM. If your animal is not down after three shots,does a fourth and fifth matter?
The first one is your best opportunity.