Here is my quandary: my girlfriend loves her PPK in 380 ACP, but she wants a little more punch in it. Would it be possible to rebarrel her PPK to 357 sig? If it is, what would be the ballpark cost? I realize that the two cartridges have vastly different shapes, one being tubular and one being necked, but is the necked profile of the 357 sig incompatible with the internal dimensions of the slide and barrel, or could it be done? Additionally, could the mags accept and feed 357 sig reliably with a little modification? I realize I'd be cutting it close in regards to OAL of the 357 sig round fitting inside the PPK mag, but could it be done?