I think shooters around here are going the other way, and looking for centerfire conversion kits for their .22's...
Seriously, rimfire ammo has been non-existent around here for a couple of years. I have enough to meet my needs, but the shelves are bare at every retail outlet.
Just this last weekend one of the local gun shops that always has tables at our gun show showed up with some obscure brand or .22 LR ammo, and cases of it. I asked what they wanted for a brick - $65.00. I told the ass hole to pound sand, that I hope he chokes on it, and I would never darken the door of his gun shop ever again. He got a little testy with me - then a couple of guys standing behind me got into it with him - "$65.00 a brick???!!! AYFKM???!!!" Then it was a dozen or so, and pretty soon a real "feeding frenzy". What that man gave up in good will in the first hour on the first day of the first gun show where he actually had rimfire ammo might just do him in in the long run. I sure hope so.
But I digress... A shooting buddy who loves SIGs has some kind of .22 conversion for one, kinda like my old Ceiner conversion for 1911's. His has always worked great - better than my Ceiner, for sure. I think SIG just came out with a scaled-down "1911" in .22 LR, didn't they? I think I looked at one at the show a couple months ago.