Lets get real here. A 2000 fps sabot slug has 500 ft lbs of KE at 500 yds and drops 236". You can't say it's equal to a rifle.
Geezer, does everything have to be stated in boring details (rhetorical question).......
Would you shoot a: 45-70, 458 WM, 458 Lott, 500NE, 505 Gibbs, 600 NE 500 yards?
Shotguns are not meant for long range shooting. But are good out to 200-300 yards, using a: scope, quality 3 inch shell, and with practice.
The 410 "shotgun" is not a gauge, but a caliber. Properly loaded: in a brass case, large rifle or large rifle magnum primer, powder charge with in SAAMI pressures plus filler, topped with a good bullet/slug.
The 410 makes the best "shotgun" when hunting in shotgun only areas/states /seasons.
Never tried nor thought to try, a 45 maxima out of a 410, but I have shot 45 long colt lead bullet cartridges out of them,.
NOTE: lead will constrict to exit the choke. I would not recommend jacketed bullets, as jacketed bullets may not constrict down to exit the muzzle.
The rifled barrel 12 gauge shotgun would be my second choice, others might choose the 20 gauge as a second choice.
I've only shot shotshells out of 16 and 28 gauges. So no experience or collected data on slugs.
And before someone says anything about KE,...As long as KE at appropriate range meets or exceeds animal weight....with proper shot placement.....animals will drop.