good day,
I spoke with the folks at P&d Enterprises in Edmonton about the sr 22 and was told they were replacing the pinned ones with a working collapsible stock.They would be a good place to start. I am pretty sure that a lot of ar 15 style stocks will fit the sr22.
On a side note, how do you like your sr22? I have been waiting for one for a month now, and I sure hope they show up soon!
Good luck with your new toy.
Ken