as they say on our side of the pond, when the government bans guns, only the government (and the criminals) will have guns.
after the successful banning and removal of all firearms from the civillian populace, the next handgun obtained by a civillian will be taken from the body of a dead police officer.
as regards the question of a sabot, as a former tank officer (and we use a good bit of sabot in the armor business) i can assure you that a sabot is a multi- part projectile, with the actual bullet/projectile (the gadget which will do the 'work' in a terminal ballistic sense) surrounded by a part or arrangement of parts which will fall away after the whole deal exits the muzzle. this allows the bullet/projectile to retain substantial muzzle velocity, thus improving ballistic efficiency by effectively increasing ballistic coefficient.
so, the answer to your question is no, prb would not count as a sabot. but, the real question is whether or not the people drafting the legislation know anything about technology of firearms.
and, of course, the underlying question is what's their real agenda? (shouldn't take rocket scientist to dope out that one).
sorry about the political tirade- check the actual wording of the legislation to see what it says. if it's like ours, the actual language is complete gobbledegook and can only be understood (and interpreted) by those who wrote it, which makes it hard to follow and really easy to enforce.