Two barrels for same gun.
 

On the other forum it was mentioned that an HSC was delivered with two barrels a .32 and a 380. Just by changing the barrels, he would be able change from .32 to 380? No problem with magazine? Would this be possible with Walther pp, Beretta 81?

This isn't uncommon. Llama's small frame autos and Erma KGP 68A also use mags that fit and work with both calibers -- not unlike .30 Luger and 9 mm for the Luger. The mags generally hold one more round in the smaller caliber than the .380. Luger mags fit the same number of each caliber.

I'd keep an eye on what the recoil springs are doing, and suspect some guns may handle one caliber better than the other due to potential strength differences.