LOL - you are right - it was late or I was inebriated when I wrote that. Seems I get more things bas-ackwards these days.
But - what I got right, was to NOT make a high pressure rifle ctg. on a shotgun action.

You could make up a 3", 12 bore rifle on a good 10 bore action, likely, to produce 1,900fps with 600gr. bullets = 4,800fpe - 700gr. bullets would make it 5,612fpe. That will kill moose.