PA Conicals are still readily available (at the moment), but sometimes they will get darned scarce. If you're gonna buy, buy a couple boxes or more and be set for the long run.
32 1/2 cents/ea from Track of the Wolf ($16.19/box)
40 cents/ea from Midway ($19.99/box)
27 cents/ea from Bud's Gun Shop ($13.45/box)
They claim they are for 1:66 twist guns. But I know first-handed that they shoot very well in a 1:20 twist T/C rifle I have. I doubt, should you try them, you'll be disappointed.