The 12 gauge is a killer, it has more power...the 20 gauge will shoot farther, flatter. When you say "latest sabot slugs", sabot slugs are nothing new. "Old style" slugs to me would mean the so called "rifled slugs" like the Remington Sluggers. They were just a lead projectile and had no sabot.
Sabots, whatever the style are best used in a rifled barrel. The newest sabot slugs have drop away type sabots and jacketed rifle bullets. They can be the most accurate and flattest shooting of them all...also the most expensive.
Personally, as far as shotgun slugs go, I like the style of the Remington Buckhammers. Of course they are no longer made...they have to do away with anything that works good. These had a sabot that stayed with the soft lead slug all the way to impact. The soft pure lead slug expanded completely and expended all of its energy on the target, rendering a quick shock kill. I have seen less than stellar performance with some of the so called newer type rifle bullet slugs. All is not lost, you can google a website called "slugs r us" and check out their "hammerhead" slugs...very easy to reload and just as accurate and effective as the old Remington Buckhammers.
As far as slug guns go, it used to be hit or miss whether or not a given shotgun would throw a slug with any accuracy. Now, the Savage bolt action shotgun is all you will ever need. This is like a very accurate big bore rifle...everyone I have seen would clover leaf slugs at 100 yards right out of the box.
