I have been trying to find CCI for 8 months. You can get it on auction sites but you are going to pay pay pay for that. 1000 rounds goes for 250 to 300 dollars. I won't pay that plus shipping. I refuse to pay 30 cents a round for 22LR That is 3 times what it should be. I'll not shoot 22 before I do that.
I have a Sig Mosquito that the owners manual says to use CCI Mini Mags in. But it eats the Remington Golden bullets pretty well. Until you can find CCI any high velosity round should work pretty well. You want at least 1280+ fps. Also be careful when finding CCI. Mini Mags will work in your 15-22 Maxi Mags will not. Mini Mags are for 22LR. Maxi Mags are for 22 Magnum. Completely different guns.
Remington 36gr hollow points are 1280 fps at the muzzle. Use that as a line. Nothing slower than 1280 fps.