The Accufab comes with an adapter to use with both PI and NPI lowers. I'm not sure about the C&L. On the Accufab, you have to bang the adapter in with a hammer or something to get it in, but you should be able to remove it when you change over to the PI. Granted, it will probably be a PITA to take it back out, but it shouldn't be too much of a problem. The instructions say to use Locktite on the adapter, but I didn't and it seems to be working fine (I'm planning a PI swap in the next few months to a year as well).