Looks like Aguila still makes them.
https://www.aguilaammo.com/rimfire/
http://ammoseek.com/ammo/22lr/Aguila-rimfire-60grains-
My ruger 10/22 cycles them no problem. It doesn’t tumble either.
I like those rounds too.
I was thinking they just never took them off their websites:
All the usual sellers had them marked as 'Discontinued', last time I checked (a few months ago), and it was discussed on some of the gun forums as well. (Colibri had been marked as discontinued too.)
I was pretty upset, having modified three firearms to use it specifically, despite that they still work fine with the regular stuff and I still had a fair amount of SSS piled-up for SHTF.. (but not enough to do much practicing).
But I see that Midway now has it "Coming Soon" and CTD has it apparently in stock.
Thanks for making me look. Guess I better stock up some more. Sadly, the price has nearly doubled. Oh Well.