I have a few for 30-06 and 30-30 ,bought them for my collection.They also came in .308 (don`t have that, but just the sabot is all I would need)
They all came in .22 cal.
Ammo One in the USA used to sell the sabots to load your own ,think he still does ?
Oh I would say about 5-6 years give or take year or two ,Scheels in the US had them for sale, but only in 30-06
BB