There are actually very few ppk's in.380, most are .32. which means a fair bit of modification if it is even allowed. I had heard that they weren't allowing 32's to change caliber but I don't know if that is true or not. PPK'S were chambered in .380 but their aren't even many of them.
Dog is right, at one time CFC wasn't allowing caliber changes from .32 in any make or model. They since changed their minds and have allowed this for the past couple of years, but are getting harder and harder to deal with. After verification, endless additional demands.
Conversion to .380 from .32 is painful. I have yet to find a reliable way to convert without cutting the frame for the new-style .380 magazines. It seems a shame to use new magazines when the .32 mags will hold and cycle .380 just fine -- but the slide lock interferes with feeding and I can't seem to grind it just right. That means a new slide lock lever (.380 style), the frame cut, and new magazines. Of course the slide's muzzle needs to be opened to the new larger diameter barrel, and the breech milled to accommodate the larger rim. Lots of fussy work, lots of potential for failure if you don't spend an eternity setting everything up. And then CFC insists on the slide marking being changed to reflect the new caliber, which is where the butchery is obvious.
There do seem to be quite a few PP and PPK pistols in .380, though .32 is by far the most common, about 8:1.
Epps has a proprietary caliber (made from .30 rifle barrels, I believe) that seemed economical, though there are no commercial loaders or reloaders for the cartridge, which would really give the new caliber and conversion some momentum. THAT is a simple barrel change, though there may still be idiotic demands to relabel the slide. I would get some professional (metal) stickers made up, if I were Epps, and ship them with the barrel, to deal with the marking issue.
