I suspect that the difficulty of "adding another rifle" due to our restrictive licensing system here in oz, is maybe the attraction to getting more broad use-age out of an already existing gun, by using sabots for example, most likely!
I've never used them myself.
I've only ever seen one used before and that was by a visiting American (Toby) who had a 12 G shotgun with an immensely long barrel (A goose gun apparently), and he used a sabot round in 12G shot shell, that had a solid brass type projectile with a plastic sabot.
He managed to shoot a big buck grey kangaroo, from fully 250 yards range, open sights, one shot kill! (I paced it out).
I was amazed!
Never seen that type of ammo in our gun shops to this day. Probably something he brought with him I am guessing - it was a good 30 years ago. Give the guy his due, he knew his business.
When he told my mate and I he was going to shoot this big buck (200lb+) Kangaroo from 250 yards with his open sighted goose scatter gun, we looked at each other, with that quizzical look of "OK which asylum did he just escape from" but a few seconds later, we were
Maybe there is a place for them...I'm guessing if they were any good long term, they would have caught on by now.