As mentioned above, they sell those at Wholesalesports, quite cheap actually, 100 for $6.49, made by S&B.
I had 5 empty casings from HC-collection with a bullet already seated, so I took my chance and made 2 rounds
1st round with 2.7 grain of Unique and the acorn 22 primer
2nd round with just the yellow (level4 power) ramset "primer", NO powder added
3rd round, just factory 32 rimfire CIL
Result: wow, that Hilti stuff really has a bang, at the top of what I would recommend, the big problem is getting the burned stuff out of the casing, therefore casing life will be shortened. Second is the factory load, third the Unique loaded round, nice and smooth, really no need using BP, so for long life 2.7 grain of Unique is perfect, maybe 3 grain for a bit more bang.
Didn't bring my chrony, next time, more professional results. Hope it still helps one or the other.